Room Lighting Calculator
Estimate how many lumens you need for a room. Multiply room area (square feet) by a lumens-per-square-foot value based on use: bedroom 10–20, kitchen 30–50, office 50–70. We use the middle of each range unless you pick a specific value.
FAQ
- What are lumens?
- Lumens measure total visible light from a source. More lumens = brighter. Wattage is power; lumens tell you actual light output.
- Why different values per room?
- Bedrooms need less ambient light; kitchens and offices need more for tasks. Guidelines are often 10–20 (bedroom), 30–50 (kitchen), 50–70 (office) lumens per sq ft.
- Can I split this across several bulbs?
- Yes. Add the lumens of all bulbs in the room to meet or exceed the total. You can mix overhead, task, and accent lights.
- What about ceiling height?
- This calculator uses area only. Very high ceilings may need more lumens or focused fixtures; small rooms may need less.
How Many Lumens for a Room?
A simple way to size room lighting is lumens per square foot. Multiply the room’s area in square feet by a target value: bedrooms often use 10–20 lumens per sq ft, kitchens 30–50, and offices or task areas 50–70. That gives total lumens needed for the space.
Home improvement calculators like this one help you buy the right bulbs or fixtures. Check packaging for lumens (not just watts). You can reach the total with one fixture or several — add up the lumens of all sources in the room. Dimmers let you reduce light when you don’t need the full amount.
Room shape, ceiling height, and finishes affect how bright it feels. Use the result as a starting point and adjust to preference. For task areas, add focused light (e.g. under-cabinet or desk lamps) on top of general ambient light.
Also try our Paint Needed Calculator for the same room.
People Also Ask
- How many lumens do I need for a room?
- How many lumens per square foot for a bedroom?
- Can I use multiple bulbs to reach the total lumens?
- Does ceiling height affect how many lumens I need?
Last updated: February 2026