The light bulb aisle has become one of the most confusing parts of any hardware store. Twenty years ago, you bought a 60-watt incandescent bulb and it lit your room. Today you’re choosing between LEDs, smart bulbs, halogens, CFLs, color temperatures, lumens, CRI ratings, A19s versus BR30s, E26 versus candelabra bases — and the federal incandescent phase-out has eliminated several familiar options entirely. This guide explains every light bulb type still sold in the United States in 2026, how to decode bulb shape and base codes, which bulb works where, what color temperature does to your eyes and sleep, and how much you can expect to spend on energy over the life of each bulb type.
The 6 Main Types of Light Bulbs Used in US Homes
Industry sources classify residential light bulbs into 4–6 categories depending on how strictly you separate technologies. The practical breakdown for US homeowners in 2026 is:
| Type | How It Works | Lifespan | Energy Efficiency | Status in US |
|---|---|---|---|---|
| LED | Semiconductor emits light when current passes through it | 25,000–50,000 hrs | ★★★★★ (75–90% less than incandescent) | Dominant standard |
| Smart bulb (LED-based) | LED with built-in WiFi, Bluetooth, or Zigbee radio | 15,000–25,000 hrs | ★★★★★ | Growing rapidly |
| Halogen | Incandescent filament + halogen gas in inner capsule | 2,000–4,000 hrs | ★★ (slightly better than incandescent) | Restricted; phasing out |
| CFL (compact fluorescent) | Mercury vapor + UV light + phosphor coating | 8,000–10,000 hrs | ★★★★ (66–75% less than incandescent) | Declining; Canada banned for 2026 |
| Fluorescent tube | Same as CFL but in T5/T8/T12 tube form | 20,000+ hrs | ★★★★ | Commercial mostly; LED tubes replacing |
| Incandescent | Electric current heats tungsten filament until it glows | ~1,000 hrs | ★ (90% energy wasted as heat) | General service bulbs banned in US since 2023 |
LED Light Bulbs: The Dominant Standard
LED stands for Light-Emitting Diode — a semiconductor that produces light when electric current passes through it. Unlike incandescent bulbs (which heat a filament) or fluorescent bulbs (which excite mercury vapor), LEDs are solid-state. No filament to break, no gas to leak, no significant heat output.
Why LED dominates in 2026
- Energy efficiency: An LED equivalent to a 60-watt incandescent draws only 8–10 watts — roughly 85% less electricity for the same brightness.
- Lifespan: 25,000–50,000 hours. At 3 hours/day, that's 22–45 years on a single bulb.
- Cool operation: Surface temperatures of 80–100°F vs. incandescent at 200–500°F. Safe to touch within seconds of switching off.
- Instant-on: Full brightness immediately, unlike CFL warm-up time.
- Dimmable: Modern dimmable LEDs work smoothly with quality dimmer switches.
- Color choice: Available in every color temperature from candle-warm 1800K to daylight 6500K.
- Shape variety: A19, A21, BR30, BR40, PAR, MR, G25, candelabra, tubular — every shape now available in LED.
What LED looks like inside
An LED bulb contains an array of small LED chips on a circuit board, a heat sink (usually aluminum fins or a metal body), a driver circuit that converts AC power to DC, and a diffuser shell. The driver is what enables features like dimming, color tuning, and smart connectivity. Quality differences between LED bulbs come down to driver quality, chip quality (CRI), and heat sink design.
For more on LED energy savings, see energy efficiency in lighting — saving money, one bulb at a time and guide to energy-efficient light options for homes.
Smart Bulbs: LED + Wireless Control
Smart bulbs are LED bulbs with a built-in wireless radio — WiFi, Bluetooth, or Zigbee/Z-Wave. They connect to your home network or a hub, and you control them through an app or voice assistant (Alexa, Google Home, Apple HomeKit).
Smart bulb features worth paying for
- Color-changing (RGB or RGBW): 16 million color options for accent and mood lighting.
- Tunable white (CCT): Same bulb shifts from 2700K warm to 5000K cool throughout the day, supporting circadian rhythm.
- Dim-to-warm: As brightness decreases, color temperature warms — mimicking incandescent dimming behavior.
- Scheduled scenes: Bulbs automatically dim and warm at sunset, brighten and cool at sunrise.
- Voice control: Hands-free dimming while cooking or on/off without getting up.
- Away-from-home control: Turn lights on/off remotely for security or because a kid won't settle.
- Motion-triggered: Combined with smart switches, lights activate on entry.
Major US smart bulb brands in 2026
| Brand | Protocol | Hub Required? | Best For |
|---|---|---|---|
| Philips Hue | Zigbee + Bluetooth | Hue Bridge for full features | Whole-home systems; widest ecosystem |
| LIFX | WiFi | No hub needed | Color quality; no extra hardware |
| TP-Link Kasa | WiFi | No hub needed | Budget-friendly smart lighting |
| Wyze Bulb | WiFi + Bluetooth | No hub needed | Inexpensive entry point |
| GE Cync | Bluetooth Mesh | No hub needed | Basic smart functions |
| Lutron Caséta | Lutron Clear Connect | Smart Bridge required | Reliable dimming; works with any LED |
Halogen Bulbs
Halogen bulbs are technically a subcategory of incandescent — they still use a tungsten filament that heats up to produce light. The difference: the filament sits inside a small inner capsule filled with halogen gas (typically iodine or bromine), which recycles evaporated tungsten back onto the filament. This extends bulb life and allows the filament to run hotter, producing brighter, whiter light.
Halogen advantages and disadvantages
| Pros | Cons |
|---|---|
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Current status: Halogen bulbs for general service applications were eliminated in the US by the 2023 DOE 45-lumen-per-watt rule. Specialty halogens (oven bulbs, certain track lighting, automotive headlights) remain available. For most home applications, LED has fully replaced halogen.
CFL & Fluorescent Tube Bulbs
CFL stands for Compact Fluorescent Lamp — essentially a long fluorescent tube folded into a spiral that fits into a standard light bulb socket. CFLs work the same way as the 4-foot T8 tubes you see in office ceilings and commercial spaces.
How CFLs work
Electric current passes through mercury vapor inside the tube, exciting the mercury atoms and producing invisible ultraviolet light. The UV light hits a phosphor coating on the inside of the tube, which converts it to visible light. This indirect process is significantly more efficient than incandescent (which mostly wastes energy as heat), but less efficient than LED (which converts electricity directly to light at the semiconductor level).
CFL advantages and disadvantages
| Pros | Cons |
|---|---|
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Fluorescent tubes (T5, T8, T12)
The long tube fluorescent bulbs in garages, basements, and commercial spaces work on the same principle as CFLs. T8 and T12 tubes are still common in older fixtures. LED tube replacements (often called "LED retrofit tubes" or "TLEDs") drop directly into existing fluorescent fixtures with either ballast bypass or ballast-compatible designs. The energy savings typically pay back the LED tube cost within 12–24 months.
Incandescent Bulbs & Edison/Filament Bulbs
Traditional incandescent bulbs work by passing electric current through a thin tungsten filament. The filament's resistance to the current causes it to heat up to roughly 4,500°F, producing visible light along with a great deal of heat. About 90% of the energy used by an incandescent bulb is wasted as heat — which is why this technology has been phased out across most of the world.
Current US status
General service incandescent bulbs (the standard 40W, 60W, 75W, 100W A19 bulbs in our parents' homes) were effectively banned in the United States in August 2023 when the DOE's 45-lumen-per-watt rule took effect. Most specialty incandescent applications also fall under the rule. Exceptions remain for:
- Appliance bulbs (refrigerator, oven, microwave)
- Plant grow lights
- Black lights and bug lights
- Marine signal lamps and certain industrial uses
- Specific shatter-resistant bulbs for food service
Edison & vintage filament bulbs
Edison-style filament bulbs — exposed amber filaments in clear glass globes — have become hugely popular as decorative fixtures in restaurants, cafes, and homes designed in industrial, farmhouse, or vintage aesthetics. The good news: nearly all "Edison filament" bulbs sold today are actually LED filament bulbs. They look identical to vintage incandescents but use 80–90% less energy and last 10–20× longer.
When buying decorative filament bulbs, check the package — it will say "LED filament" rather than "incandescent." Edison filament LEDs are available in A19, ST64 (curved teardrop), G25 (globe), G40 (large globe), and tubular T10/T14 shapes.
Light Bulb Shape Codes Explained
Bulb shape codes look intimidating — A19, BR30, PAR38, MR16, T8 — but they follow a simple system. The letter(s) indicate the bulb shape; the number indicates the bulb's diameter at its widest point, measured in 1/8 inch increments.
A = "Arbitrary" — the classic pear/standard bulb shape
19 = 19/8 inch diameter = 2.375 inches across
Decoding BR30:
BR = "Bulged Reflector" — wide-flood reflector bulb
30 = 30/8 inch diameter = 3.75 inches across
Decoding PAR38:
PAR = "Parabolic Aluminized Reflector" — focused-beam outdoor floodlight
38 = 38/8 inch diameter = 4.75 inches across
Common bulb shapes for US homes
The Light Bulb Shape Family
The standard household bulb. Most common size in America. Fits virtually any standard E26 socket — table lamps, ceiling fixtures, floor lamps, pendants.
Slightly larger than A19. Used in higher-wattage equivalents and in larger lamps where a small A19 looks lost.
Bulged Reflector flood bulbs. Recessed ceiling cans, indoor floodlights. BR30 for standard 6" cans; BR40 for larger 7–8" cans.
Parabolic Aluminized Reflector. Focused beam. Outdoor flood/spot lighting, accent track lighting. Higher wattage and brighter than BR equivalents.
Multifaceted Reflector. Concentrated narrow beam. Track lighting, accent lighting, display cases. Bi-pin GU5.3 base for low-voltage; GU10 base for line-voltage.
Globe shape. Bathroom vanity bars, makeup mirrors, large decorative pendants. G25 = 3.125" diameter; G40 = 5" diameter.
Candle-flame shaped. Chandeliers, sconces, decorative fixtures. B = blunt tip; C = conical; CA = candelabra angled tip. Usually E12 base.
Long tube fluorescent or LED. Garage shops, basements, commercial fixtures. T8 = 1" diameter; T12 = 1.5" diameter.
Light Bulb Base Types Explained
The base is the part that screws or plugs into the socket. Base type is independent of bulb shape — an E26 base appears under A19s, BR30s, PAR38s, globe G25s, and many others. The letter indicates the base style; the number indicates the diameter or pin spacing in millimeters.
Screw-base types (Edison Screw)
| Base Code | Name | Diameter | Where You'll Find It |
|---|---|---|---|
| E26 | Medium / Standard (US) | 26 mm (1.024") | The standard US household base. A19, BR30, PAR, globe — most everything. |
| E27 | Medium (Europe) | 27 mm (1.063") | European equivalent of E26. Rated for 220–240V; not for US use. |
| E12 | Candelabra | 12 mm (0.472") | Chandelier candle bulbs, decorative sconces, small night lights. |
| E17 | Intermediate | 17 mm (0.669") | Appliance bulbs (some refrigerators, microwaves), desk lamps, Christmas C9 strings. |
| E11 | Mini-Candelabra | 11 mm (0.433") | Small chandelier-style decorative bulbs. |
| E39 | Mogul | 39 mm (1.535") | High-bay commercial fixtures, outdoor street lamps, large HID bulbs. |
Pin-base types (twist-lock and bi-pin)
| Base Code | Name | Pin Spacing | Where You'll Find It |
|---|---|---|---|
| GU10 | Twist-lock bi-pin | 10 mm | Track lighting, recessed downlights, residential spotlights. 120V line voltage. |
| GU24 | Twist-lock | 24 mm | Energy-efficient fixtures (designed to prevent incandescent retrofit). California Title 24 compliant. |
| GU5.3 / G5.3 | Push-in bi-pin | 5.3 mm | MR16 low-voltage track and accent lighting. Requires transformer (12V). |
| G4 / GY6.35 | Mini bi-pin | 4 mm / 6.35 mm | Under-cabinet halogen capsules, landscape lighting. |
| G13 | Bi-pin (tubes) | 13 mm | T8 fluorescent and LED tube replacements. |
Color Temperature: What Kelvin Numbers Actually Mean
Color temperature describes the color of the light a bulb produces, measured in Kelvin (K). Lower numbers = warmer (yellow/orange); higher numbers = cooler (white/blue). It has nothing to do with actual heat output.
Color Temperature Spectrum
Night light range
Bedroom, living room
Kitchen, dining, bath
Garage, office, basement
Workshop, display
| Color Temp | US Marketing Name | Effect | Best For |
|---|---|---|---|
| 1800–2200K | Candle / Amber | Warm orange glow; melatonin-safe | Night lights, bedtime, romantic dining |
| 2400–2700K | Soft White / Warm White | Classic incandescent warmth | Living rooms, bedrooms, dining rooms, hallways |
| 3000K | Warm White / Bright White | Clean warm glow | Kitchens, bathrooms, dining |
| 3500K | Neutral White | Neither warm nor cool | Offices, retail, transitional spaces |
| 4000K | Cool White | Crisp daylight feeling | Garages, offices, basements, task lighting |
| 5000K | Daylight | Slightly blue, alert | Workshops, makeup vanities, retail display |
| 6000–6500K | Daylight / Cool Daylight | Strong blue-white | Commercial display, security lighting |
Lumens, Watts & Energy Efficiency
The old measurement for light bulb brightness was watts — but watts measure energy consumption, not brightness. With LEDs, a 9W LED produces the same light as a 60W incandescent. The accurate brightness measurement is lumens.
Lumens-to-watts equivalency for LED replacement
| Light Output | Old Incandescent Wattage | LED Wattage Today | CFL Wattage | Halogen Wattage |
|---|---|---|---|---|
| 450 lumens | 40W | 5–6W | 9–11W | 28W |
| 800 lumens | 60W | 8–10W | 13–15W | 42W |
| 1100 lumens | 75W | 10–12W | 18–20W | 53W |
| 1600 lumens | 100W | 14–17W | 23–25W | 72W |
| 2600 lumens | 150W | 22–25W | 32W | 105W |
How many lumens does your room need?
Use this rule of thumb: multiply room square footage by the lumens per square foot for that room type.
| Room Type | Lumens per Sq Ft | Example (200 sq ft) |
|---|---|---|
| Living room (ambient) | 10–20 | 2,000–4,000 lumens |
| Bedroom (ambient) | 10–20 | 2,000–4,000 lumens |
| Kitchen (general) | 30–40 | 6,000–8,000 lumens |
| Kitchen (task at counter) | 70–80 | 500–800 lumens at the counter directly |
| Bathroom (general) | 70–80 | 1,400–1,600 lumens |
| Bathroom (vanity) | 70–80 | 1,000+ lumens at face level |
| Dining room | 30–40 | 6,000–8,000 lumens |
| Home office (general) | 60–80 | 1,200–1,600 lumens |
| Home office (task at desk) | n/a (task lamp) | 500–800 lumens at the desk |
| Hallway | 5–10 | 1,000–2,000 lumens |
| Garage / workshop | 50–80 | 10,000–16,000 lumens |
For deeper room-by-room sizing, see how much light does my room need.
10-year cost comparison (single bulb, 3 hours/day, $0.16/kWh)
| Bulb Type | Bulb Cost (10 years) | Electricity (10 years) | Total 10-Year Cost |
|---|---|---|---|
| Incandescent (60W) | ~$15 (15 bulbs) | ~$105 | ~$120 |
| Halogen (43W) | ~$24 (8 bulbs) | ~$75 | ~$99 |
| CFL (13W) | ~$6 (2 bulbs) | ~$23 | ~$29 |
| LED (9W) | ~$5 (1 bulb) | ~$16 | ~$21 |
A single LED bulb saves roughly $100 in electricity over 10 years compared to an incandescent. Across a typical 30-bulb US home, that's roughly $3,000 in lifetime savings — without counting the labor cost of replacing burned-out bulbs 15 times.
CRI & Beam Angle
CRI: Color Rendering Index
CRI measures how accurately a bulb shows colors compared to natural sunlight, on a 0–100 scale. Sunlight is 100. A CRI of 90+ means colors look natural and vivid. A CRI of 60–80 means colors look slightly washed out or off-tinted. Cheap LED bulbs often have CRI 70–80; quality LEDs have CRI 90+.
- CRI 95+: Photography, art galleries, makeup application, retail display
- CRI 90–95: Quality residential lighting; recommended for kitchens, bathrooms, kids' rooms
- CRI 80–90: Standard quality; acceptable for most general lighting
- CRI <80: Avoid — colors look flat and unnatural
Beam angle
Beam angle measures how wide the cone of light is from a bulb, in degrees. A "spot" bulb has a narrow beam (10–25°); a "flood" bulb has a wide beam (40–60°+); a standard A19 bulb has no defined beam angle because it emits light in all directions (omnidirectional, roughly 320°).
| Beam Angle | Marketing Term | Best For |
|---|---|---|
| 10–18° | Narrow spot | Accenting artwork, sculptures, architectural features |
| 20–25° | Spot | Track lighting, retail accent, gallery lighting |
| 30–40° | Narrow flood | General accent, recessed accent cans |
| 40–60° | Flood | General ambient recessed lighting |
| 60°+ | Wide flood | Wash lighting, outdoor security floods |
| 320° (A19) | Omnidirectional | Table lamps, ceiling fixtures, general use |
Special Bulb Types
Dimmable LEDs
Not all LEDs are dimmable — check the package label. Dimmable LEDs work smoothly with compatible dimmer switches. Older incandescent-only dimmers may cause flickering or buzzing with LEDs; for best results, install LED-compatible dimmers (Lutron, Leviton).
3-way bulbs
3-way bulbs have two filaments (incandescent) or two sets of LEDs that operate independently — low, medium, and combined (high). Requires a 3-way socket and a matching 3-way switch. Common in bedside lamps and floor lamps.
Anti-blue-light / sleep-friendly bulbs
Specialty LED bulbs marketed for sleep support filter out blue wavelengths (typically below 460nm). Used in bedrooms, kids' rooms, and bedside reading lamps. The same effect can be achieved with any 2200K–2400K warm-amber LED.
Bug-light / yellow bulbs
Yellow-coated bulbs that emit minimal blue and UV light, attracting fewer flying insects. Used on porches and outdoor entries. Available in LED.
Room-by-Room Bulb Recommendations
Kitchen
Browse kitchen lighting for compatible fixtures.
Bedroom
Browse bedroom lighting. See 12 tips for choosing the perfect bedside lamp.
Living Room
Bathroom & Vanity
Browse bathroom lighting.
Dining Room
Browse dining room lighting and chandeliers.
Foyer / Entryway
For specifics, see 5 best foyer lighting bulb types for your home. Browse foyer lighting.
Home Office
Garage / Workshop / Basement
International Terminology — What "Light Bulb" Means Worldwide
If you've ever wondered why some Australian sources say "light globe" or why UK packaging uses different wattage equivalents, here's the breakdown:
| Term | Region | Meaning |
|---|---|---|
| Light bulb | US, Canada | Standard term |
| Lightbulb (one word) | US informal | Same thing |
| Light globe | Australia, New Zealand | Same as "light bulb" |
| Lamp / bulb | UK, technical | "Lamp" in industry terminology means the bulb itself; "luminaire" means the fixture |
| Electric bulb | India, Pakistan, parts of Asia | Same as "light bulb" |
| Bombilla / lámpara | Spanish-speaking | Same as "light bulb" |
| Lampu | Indonesia, Malaysia | Same as "light bulb" |
Disposal & Recycling
| Bulb Type | How to Dispose | Why |
|---|---|---|
| LED | Regular trash OK in most US states; recycling preferred (electronics recycling at Home Depot, Lowe's, Best Buy) | No mercury or hazardous materials |
| Incandescent / Halogen | Regular trash. Wrap in paper to prevent glass cuts. | No hazardous materials, but glass |
| CFL / Fluorescent tube | Hazardous waste only. Home Depot, Lowe's, and most municipal hazardous waste programs accept CFLs. Never throw in regular trash. | Contains mercury — toxic to soil and water if landfilled |
| Smart bulbs | Electronics recycling (Best Buy, Staples, municipal e-waste programs) | Contains circuit board and radio components |
7 Common Light Bulb Mistakes
- Buying watts instead of lumens. A 60W incandescent ≠ a 60W LED. A 9W LED replaces a 60W incandescent. Buy by lumens (800 lumens = standard living room A19).
- Wrong color temperature in bedroom. 4000K+ bulbs suppress melatonin and delay sleep. Stick to 2700K or lower in bedrooms.
- Cheap LEDs in important rooms. Low-CRI LEDs (under 80) make food, skin, and fabrics look unnatural. Pay extra for CRI 90+ in kitchens, bathrooms, and dining rooms.
- Non-dimmable LED on a dimmer. Flickering, buzzing, and short bulb life. Check the package for "dimmable" before installing on a dimmer switch.
- BR30 in an A19 fixture. Same base (E26), but the BR30 is too large to fit inside an enclosed fixture. Shape matters as much as base.
- Halogen near fabrics. The UV emission and 200–250°F surface temperature can scorch lampshades and fade fabrics over time.
- CFL in the trash. Mercury contamination. Always return CFLs to hazardous waste collection.
Browse Seus Lighting's complete fixture collections — chandeliers, pendant lighting, wall sconces, ceiling fixtures, and bathroom vanity lighting. Every fixture is rated for the bulb types and bases described above.
Shop Chandeliers Shop Pendant Lighting
Frequently Asked Questions
What are the 3 main types of light bulbs?
The three main types of light bulbs most commonly compared are LED, CFL (compact fluorescent), and incandescent. LED is the most energy-efficient, lasting 25,000–50,000 hours while using about 75–90% less energy than incandescent. CFL uses 66–75% less energy than incandescent but contains mercury. Incandescent is the traditional filament bulb, now largely phased out in the US under 2023 DOE efficiency rules. Halogen, fluorescent tubes, and smart bulbs are also common, making 5–6 types in total.
What are the 4 main types of light bulbs?
The four primary light bulb types are LED (light-emitting diode), CFL (compact fluorescent lamp), halogen, and incandescent. LED is now the dominant standard for US homes, offering the longest lifespan and lowest energy use. Halogen and incandescent are largely phased out in the US under 2023 DOE rules. CFL is declining due to mercury content. Add fluorescent tubes and smart bulbs for a more complete picture of what's actually used today.
What are the 5 different types of light bulbs?
The five most common light bulb types are incandescent, halogen, CFL (compact fluorescent), fluorescent tube, and LED. Smart bulbs (which are LED-based) make a sixth category if separated. In US homes today, LED dominates — incandescent and most halogens were phased out in 2023, and CFLs are declining due to mercury content. Each type uses a different mechanism to produce light, with significantly different energy efficiency and lifespan.
How many types of light bulbs are there?
There are 6 main types of light bulbs used in homes today: LED, smart bulbs (LED-based), halogen, CFL, fluorescent tube, and incandescent. Some classifications add HID (high-intensity discharge — used for stadiums and street lighting) for 7 total. Specialty bulbs like UV, infrared, grow lights, and bug lights are additional subtypes, but for residential US lighting purposes, the 6 main types cover virtually every application.
Which type of light bulb is best for home use?
LED is the best light bulb type for home use in 2026, by every meaningful metric — lowest energy consumption (75–90% less than incandescent), longest lifespan (25,000–50,000 hours), cool to the touch (80–100°F surface), instant-on at full brightness, available in every shape and color temperature, and free of mercury. The only situation where LED isn't automatically the answer is for specific specialty applications like oven bulbs or shatter-resistant food-service bulbs.
What does A19 mean on a light bulb?
A19 is a shape code. The letter "A" stands for "Arbitrary" — the standard pear/teardrop shape of a classic household light bulb. The number "19" indicates the bulb's diameter at its widest point, in 1/8 inch increments — so 19/8 = 2.375 inches (about 60mm) wide. A19 is the most common US household bulb shape and typically pairs with an E26 medium screw base. Same shape can pair with different bases depending on the fixture (E26, E27, sometimes E12).
What is the difference between E26 and E27 bulbs?
E26 is the US standard medium screw base (26mm diameter, rated for 120V). E27 is the European equivalent (27mm diameter, rated for 220–240V). They look nearly identical and often physically fit each other's sockets, but the 1mm difference and the voltage difference matter. For new installations in the US, always use E26. E27 bulbs sold for European markets are not rated for US 120V electrical systems and should not be used.
What's the difference between warm white and soft white?
In US bulb marketing, "soft white" usually refers to 2700K (the classic warm incandescent glow) and "warm white" usually refers to 3000K (slightly cleaner warmth, common in kitchens). The terms are used inconsistently across brands. The reliable indicator is the Kelvin (K) number on the package: 2700K = soft white; 3000K = warm white; 4000K = cool white / bright white; 5000K = daylight. Always check the K rating rather than the marketing name.
Are incandescent light bulbs still sold in the US?
Most general service incandescent bulbs have been banned from US sale since August 2023, when the Department of Energy's 45-lumen-per-watt rule took effect. Specific exemptions remain for appliance bulbs (refrigerator, oven), plant grow lights, black lights, bug lights, marine signal lamps, and shatter-resistant food-service bulbs. Standard 40W, 60W, 75W, and 100W A19 incandescent bulbs are no longer available for general home use. LED replacements are the standard alternative.
What color temperature is best for sleep?
2200K–2700K (warm amber to soft white) is best for the hour before sleep — it doesn't suppress melatonin production. For night lights, choose 2200K amber or red LED, which has minimal effect on melatonin. Avoid 4000K+ cool white or daylight bulbs in bedrooms and evening areas — they can delay sleep onset by 30–60 minutes by suppressing the body's natural melatonin rise. Children are even more sensitive to evening blue light than adults.
How long do LED bulbs really last?
Quality LED bulbs are rated for 25,000–50,000 hours of operation. At 3 hours per day, that's 22–45 years on a single bulb. Real-world lifespan varies based on heat exposure (enclosed fixtures shorten life), driver quality (cheap drivers fail before LEDs do), and on/off cycling frequency. LEDs don't "burn out" like incandescent — they gradually dim. The L70 rating tells you when the bulb will have dropped to 70% of its original brightness.
Can I put any LED bulb in any fixture?
Three things must match: base type (E26, E12, GU10, etc.), bulb shape (A19, BR30, candelabra — the fixture must have physical clearance), and dimmable compatibility (if the fixture has a dimmer, the LED must be dimmable). Also check for enclosed fixture rating — some LEDs aren't rated for fully enclosed fixtures because the heat shortens their life. The package will say "suitable for enclosed fixtures" if compatible.
Final Thoughts
The era of confusion in the light bulb aisle ends when you know three things: the bulb shape your fixture needs (A19, BR30, candelabra, etc.), the base size of the socket (E26, E12, GU10), and the color temperature you want (2700K for bedrooms, 3000K for kitchens, never 4000K+ in evening rooms). For nearly every US home application in 2026, the right answer is an LED bulb — dimmable, CRI 90+, in the appropriate shape and base for your fixture, in a color temperature that matches the room's use. Smart bulbs add convenience and circadian-supportive scheduling for those willing to invest in the ecosystem.
For more lighting depth, browse our connected guides: energy efficiency in lighting, guide to energy-efficient light options, comprehensive color temperature guide, how much light does my room need, 5 best foyer lighting bulb types, 9 best light colors for studying, and how to change a bulb in a high-ceiling chandelier.
