Lumens Calculator (How Bright a Light Do I Need?)
Lumens Calculator
Find how many lumens a room needs for comfortable lighting, based on room size and how the space is used.
A general guideline using the foot-candle method (lumens = area × foot-candles). Actual needs vary with ceiling height, wall color, fixture type and personal preference. Layer ambient, task and accent lighting.
More free tools:PaintTileLumensWire GaugeConcreteBoard FootFan SizeVoltage DropMERV FinderBulb BrightnessAll tools →
How many lumens does a room need?
Multiply the room’s square footage by the target foot-candles for that space. A 12×12 kitchen (144 sq ft) at 35 foot-candles needs about 5,000 lumens total — best split across several fixtures rather than one bright light. See our lumens vs watts guide to convert to bulb wattage.
| Room | Foot-candles |
|---|---|
| Living room / bedroom | 10-20 |
| Kitchen / dining | 30-40 |
| Bathroom vanity | 70-80 |
| Workshop / office | 50 |