How many lumens do you need to light a room properly? This free lumens calculator uses your room type, size, ceiling height and wall color to work out the total brightness you need, how many LED bulbs to buy, the best color temperature, and what it costs to run. No more rooms that feel gloomy or harsh.
Lumens Calculator
Find how many lumens and bulbs any room needs, plus the right color temperature.
Based on recommended foot-candle (lumens per sq ft) ranges for homes. LED efficiency assumed at 90 lumens per watt.
How to Use the Lumens Calculator
- Choose the room type. Kitchens, bathrooms and offices need far more light than bedrooms or hallways.
- Enter the room length and width in feet or meters.
- Pick ceiling height and wall color. High ceilings and dark walls absorb light, so you need more lumens.
- Select the bulb you want to buy to see how many you need.
The Lumens Formula
Lumens needed = room area (sq ft) × foot-candles for the room
A foot-candle is one lumen per square foot. The tool then adds about 10% per extra foot of ceiling height and up to 25% for dark walls and floors.
Example: a 15 × 13 ft living room is 195 sq ft. At 15 foot-candles it needs about 2,900 lumens, which is four 800-lumen LED bulbs (60 W equivalent) using only around 32 watts in total.
Lumens per Square Foot by Room
| Room | Lumens per sq ft | Color temperature |
|---|---|---|
| Living room | 10 – 20 | 2700K – 3000K |
| Bedroom | 10 – 20 | 2700K |
| Kitchen (general) | 30 – 40 | 3000K – 4000K |
| Kitchen counters | 70 – 80 | 4000K |
| Dining room | 30 – 40 | 2700K – 3000K |
| Bathroom vanity | 70 – 80 | 3000K – 4000K |
| Home office | 50 – 70 | 4000K – 5000K |
| Hallway | 5 – 10 | 2700K – 3000K |
| Garage / workshop | 50 – 70 | 5000K |
Lumens to Watts: LED vs Incandescent
| Brightness | Old incandescent | LED bulb |
|---|---|---|
| 450 lumens | 40 W | 4 – 6 W |
| 800 lumens | 60 W | 8 – 10 W |
| 1,100 lumens | 75 W | 11 – 13 W |
| 1,600 lumens | 100 W | 15 – 18 W |
See exactly how much you save by switching with our LED vs incandescent savings calculator.
Smart Lighting Tips
- Use tunable white smart bulbs to shift from cool light in the morning to warm light in the evening.
- Spread light over several fixtures instead of one very bright ceiling light.
- Add motion sensor bulbs or switches in hallways, closets, laundry rooms and garages.
- Choose bulbs with a CRI of 90 or higher in kitchens and bathrooms for true-to-life colors.
Frequently Asked Questions
How many lumens do I need for a living room?
A living room needs about 10 to 20 lumens per square foot. A 200 sq ft living room needs roughly 2,000 to 4,000 lumens, or three to five 800-lumen LED bulbs.
How many lumens is good for a bedroom?
Bedrooms need 10 to 20 lumens per square foot of soft, warm 2700K light. A 12 x 12 ft bedroom (144 sq ft) needs about 1,500 to 2,900 lumens.
How many lumens do I need in a kitchen?
Plan 30 to 40 lumens per sq ft for general kitchen lighting and 70 to 80 lumens per sq ft over counters and the stove. A 150 sq ft kitchen needs about 5,000 lumens of general light.
How many lumens equal a 60 watt bulb?
A 60 W incandescent bulb gives about 800 lumens. An LED bulb produces the same 800 lumens using only 8 to 10 watts.
What color temperature is best for each room?
Use 2700K warm white for bedrooms and living rooms, 3000K to 4000K for kitchens and bathrooms, and 4000K to 5000K for offices, garages and workshops.
More Free Smart Home Tools
- LED vs Incandescent Savings Calculator – savings from switching to LED
- Appliance Energy Cost Calculator – what each appliance costs to run
- Smart Home Cost Calculator – budget for a full smart home setup
- AC BTU Calculator – find the right air conditioner size for any room
- Solar Panel Calculator – how many panels you need, cost and payback
