15×18 room:
how many lights?
9–25fixtures A 15×18 ft room is 270 square feet. How many lights it needs depends entirely on what happens in it — a kitchen is lit to roughly twice the level of a bedroom, so the same footprint ranges from 9 to 25 fixtures at 800 lumens each.
The footprint does not decide the count. The target illuminance does, and that is set by what the room is for.
SOURCE·IES lumen-method recommendations·published recommendations, quoted as ranges·REVIEWED JUL 2026
Plan above: the 15×18 ft footprint laid out as a living room at 150 lux, with iso-lux contours at 32 / 21 / 11 lux.
Schedule · by useOne 15×18 footprint, twelve commissioning targets
| Room type | Target | Total lumens | Fixtures | Grid | Spacing |
|---|---|---|---|---|---|
| Kitchen | 300 lx | 14,824 lm | 20 | 5 × 4 | 3.6′ × 3.8′ |
| Living room | 150 lx | 8,799 lm | 12 | 4 × 3 | 4.5′ × 5′ |
| Bedroom | 100 lx | 5,866 lm | 9 | 3 × 3 | 6′ × 5′ |
| Bathroom | 200 lx | 11,731 lm | 16 | 4 × 4 | 4.5′ × 3.8′ |
| Home office | 300 lx | 15,262 lm | 20 | 5 × 4 | 3.6′ × 3.8′ |
| Dining room | 150 lx | 7,631 lm | 9 | 3 × 3 | 6′ × 5′ |
| Garage | 150 lx | 8,799 lm | 12 | 4 × 3 | 4.5′ × 5′ |
| Hallway | 100 lx | 5,866 lm | 9 | 3 × 3 | 6′ × 5′ |
| Laundry | 200 lx | 9,883 lm | 12 | 4 × 3 | 4.5′ × 5′ |
| Basement | 150 lx | 8,799 lm | 12 | 4 × 3 | 4.5′ × 5′ |
| Workshop | 400 lx | 19,766 lm | 25 | 5 × 5 | 3.6′ × 3′ |
| Nursery | 100 lx | 5,866 lm | 9 | 3 × 3 | 6′ × 5′ |
At 800 lumens per fixture and an 8 ft ceiling. Open a room type for other fitting outputs, other ceilings and its own contour sheet.
SOURCE·IES lumen-method recommendations·published recommendations, quoted as ranges·REVIEWED JUL 2026
QueriesWhat this footprint is usually asked
How many recessed lights for a 15x18 room?
It depends what the room is for. A 15×18 ft (270 sq ft) living room needs about 12 fixtures at 800 lm; the same footprint as a kitchen needs about 20, because a kitchen is lit to roughly double the level. Pick the room type for the real answer.
How many square feet is a 15x18 room?
270 square feet, or 25.1 square metres.
