Light Bulb Buying Guide

Complete guide to choosing the right light bulbs: color temperature, lumens vs watts, base types, bulb shapes, and which bulb works best for each room.

Bulb Types Comparison
TypeEfficiencyLifespanCostNotes
LEDExcellent (80-90%)15-25 years$2-15+Best choice for most uses, dimmable options available
CFLGood (60-70%)7-10 years$2-8Contains mercury, being phased out
HalogenModerate (20-30%)2-3 years$2-6Runs very hot, good color rendering
IncandescentPoor (10%)1-2 years$1-3Being phased out, warm light

Bottom Line:

LED bulbs are the clear winner for energy savings, longevity, and total cost of ownership. A $5 LED replacing a 60W incandescent saves approximately $150 in electricity over its lifetime.

Color Temperature (Kelvin Scale)

Understanding Color Temperature

Color temperature is measured in Kelvin (K). Lower numbers = warmer/yellower light. Higher numbers = cooler/bluer light. This dramatically affects the mood and function of a space.

KelvinNameAppearanceBest For
2200KCandlelightVery warm amber/orangeAccent lighting, mood lighting
2700KSoft WhiteWarm yellow/orangeBedrooms, living rooms, dining rooms
3000KWarm WhiteWarm white with yellow tintKitchens, bathrooms, general purpose
3500KNeutral WhiteBalanced warm/coolOffices, retail, workspaces
4000KCool WhiteCrisp white with blue tintGarages, laundry, task areas
5000KDaylightBright bluish-whiteReading, craft rooms, workshops
6500KDaylight DeluxeVery blue/harshDetail work, photography, aquariums

Warm Light (2700K-3000K)

Creates relaxing, cozy atmosphere. Makes skin tones look flattering. Best for spaces where you want to unwind.

Cool Light (4000K-5000K)

Increases alertness and focus. Better for task lighting and productivity. Can feel sterile in living spaces.

Lumens vs Watts Guide

Shop by Lumens, Not Watts

Watts measure energy use, not brightness. Lumens measure actual light output. With LED technology, you get more lumens per watt - that's the efficiency gain.

BrightnessLumensLED Watts"Equivalent" IncandescentBest Use
Low250-4504-5W25-40WAccent, nightlights, closets
Medium8008-10W60WGeneral purpose, most rooms
Bright110012-14W75WKitchens, reading areas
Very Bright160016-20W100WWork areas, garages
Maximum2600+25-30W150WWorkshops, commercial

Energy Savings Example

Replacing a 60W incandescent with an 9W LED (both 800 lumens) saves 51 watts. Running 3 hours/day = 56 kWh/year saved = ~$7-14/year per bulb at typical electricity rates.

Common Base Types
Base CodeNameDiameterCommon Uses
E26 / E27Medium Edison Screw26mm (1")Standard household - lamps, ceiling fixtures
E12Candelabra12mm (~1/2")Chandeliers, decorative fixtures, night lights
E17Intermediate17mmAppliances, ceiling fans (less common)
GU10Twist & Lock10mm pinsTrack lighting, recessed downlights
GU24Two-Pin Twist24mm pinsEnergy-efficient fixtures (Title 24)
MR16 / GU5.3Bi-Pin (Low Voltage)5.3mm pinsTrack lighting, landscape, 12V systems
G4Bi-Pin Tiny4mm pinsUnder-cabinet, RV, boat lights
G9Bi-Pin Loop9mm pinsDecorative fixtures, pendants

Pro Tip: Bring the Old Bulb

When shopping for replacements, bring your old bulb to ensure exact match. E26 and E27 bases are interchangeable (E27 is metric equivalent).

Bulb Shape Codes

Understanding Shape Codes

The letter indicates shape (A=Arbitrary, B=Bullet, C=Candle, G=Globe, PAR=Parabolic, etc.). The number is the diameter in eighths of an inch (A19 = 19/8" = 2.375" diameter).

ShapeCommon SizesDescriptionCommon Uses
A (Arbitrary)A15, A19, A21Classic pear/bulb shapeTable lamps, ceiling fixtures, anywhere
BR (Bulged Reflector)BR30, BR40Wide flood beam, domed frontRecessed can lights (most common)
PAR (Parabolic)PAR20, PAR30, PAR38Focused beam, glass lensTrack lights, outdoor floods, spotlights
MR (Multifaceted)MR11, MR16Small reflector, focusedTrack lighting, display, landscape
B/C/CA (Candle)B10, C7, CA10Decorative candle/bulletChandeliers, sconces, decorative
G (Globe)G16.5, G25, G40Round ball shapeVanity mirrors, pendant lights
T (Tubular)T8, T10, T12Tube shapeFluorescent replacements, showcases
ST (Edison)ST18, ST19, ST64Vintage teardrop shapeExposed bulb fixtures, industrial style
Recessed Can Light Sizing
Can SizeOpening DiameterBulb TypeNotes
4"~3.5" openingBR20, PAR20, MR16Smaller spaces, accent lighting
5"~4.5" openingBR30, PAR30Common residential size
6"~5.5" openingBR30, BR40, PAR38Most common - kitchens, living areas
8"~7" openingBR40, PAR38Commercial, high ceilings

LED Retrofit Options:

You can replace entire recessed fixtures with LED retrofit kits that include integrated trim and LED module. These are more efficient than replacing just the bulb and often dimmable.

Room-by-Room Recommendations

Living Room

  • 2700K-3000K for ambient lighting
  • Dimmable LEDs for flexibility
  • 800-1100 lumens per fixture
  • Mix of overhead and lamps

Kitchen

  • 3000K-4000K for task visibility
  • 1100+ lumens for work areas
  • Under-cabinet LEDs (3000K)
  • Recessed cans: BR30 or BR40

Bedroom

  • 2700K for relaxing atmosphere
  • Dimmable for bedtime
  • 450-800 lumens (softer)
  • Reading lights: 3000K focused

Bathroom

  • 3000K-4000K for grooming
  • Vanity: G25 globe bulbs or bars
  • 800-1600 lumens total
  • Shower: Wet-rated LEDs

Garage/Workshop

  • 4000K-5000K for visibility
  • High lumens (1600+ per fixture)
  • LED shop lights or tubes
  • Task lighting: 5000K

Outdoor

  • 2700K-3000K for ambiance
  • 4000K+ for security
  • Wet-rated and enclosed rated
  • Motion sensor compatible
Dimmable LED Considerations
  • Check Compatibility: LED must be labeled "dimmable" - not all LEDs work with dimmers
  • Dimmer Type Matters: Use LED-compatible dimmers (not old incandescent dimmers)
  • Minimum Load: Some dimmers require minimum wattage; LEDs may be too efficient
  • Flickering Issues: Usually caused by incompatible dimmer or poor-quality LED
  • Brand Matching: Dimmer manufacturers list compatible LED bulb brands

Common Dimmer Brands

Lutron, Leviton, and Legrand all make quality LED-compatible dimmers. Check their websites for LED bulb compatibility lists before purchasing.

CRI: Color Rendering Index

What is CRI?

CRI measures how accurately a light source renders colors compared to natural light (100 CRI). Higher CRI means colors look more natural and vibrant under that light.

CRI RatingQualityBest For
90-100ExcellentArt studios, retail, makeup, photography
80-89GoodHomes, offices, general residential (minimum recommended)
60-79ModerateGarages, storage, utility areas only

For living spaces, always choose bulbs with CRI 80 or higher. CRI 90+ is worth the extra cost for kitchens, bathrooms, and anywhere you want colors to look natural.

Smart Bulb Features

WiFi Bulbs

  • Connect directly to router
  • No hub required
  • May slow WiFi with many bulbs
  • Examples: LIFX, Wyze, some Philips

Zigbee/Z-Wave Bulbs

  • Require hub (Hue Bridge, SmartThings)
  • More reliable, don't burden WiFi
  • Create mesh network
  • Examples: Philips Hue, Sengled

Smart Bulb Considerations:

  • Switches must stay ON - use smart switches instead if this is an issue
  • Color-changing bulbs cost more ($15-50+) vs white-only smart bulbs ($8-15)
  • Check compatibility with your voice assistant (Alexa, Google, HomeKit)

Additional Information

About This Light Bulb Buying Guide

This comprehensive light bulb buying guide is designed for homeowners who want to make informed decisions when purchasing light bulbs for their homes. With the transition from incandescent to LED technology, understanding color temperature, lumens, and base types has become essential for creating the right lighting atmosphere in each room.

Whether you're replacing a burned-out bulb, upgrading to energy-efficient LEDs, or planning lighting for a renovation, this guide covers everything you need to know. We explain the difference between warm and cool light, how to read lumens instead of watts, which bulb shapes fit which fixtures, and how to choose the right color temperature for each room in your home.

LED bulbs have revolutionized home lighting with their energy efficiency, long lifespan, and versatility. While they cost more upfront than incandescent bulbs, they save significant money over time through reduced energy bills and fewer replacements. This guide helps you navigate the many LED options available today to find the perfect bulbs for your needs.

Why Use This Light Bulb Reference Guide?

Choosing the right light bulb affects your home's comfort, energy bills, and the way colors appear in your spaces. This guide helps you make informed decisions every time you shop for bulbs.

  • Understand color temperature (Kelvin) to create the right mood in each room
  • Shop by lumens to get the brightness you need, not wattage guesswork
  • Identify the correct base type for any fixture in your home
  • Choose the right bulb shape for recessed lights, chandeliers, and more
  • Calculate energy savings when switching to LED technology
  • Select dimmable bulbs that work with your existing dimmer switches
  • Find the best color rendering (CRI) for natural-looking colors
Frequently Asked Questions

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