Amit's data tools
LuxPlan
120 sq ft · 300 lux target

10×12 kitchen:
9 lights

9 fixtures A 10×12 ft kitchen (120 sq ft) needs approximately 9 recessed lights at 800 lumens each — about 7,655 lumens in total — laid out 3 across by 3 deep.

Space them 4 ft apart along the 12 ft wall and 3.3 ft apart along the 10 ft wall, starting 2 ft from the end walls.

Fixtures9at 800 lm each
Total lumens7,655to hit 300 lux
Spacing4′× 3.3′ apart
Wall offset2′from the end wall

The ceiling plan

Drawn to scale, with each fixture at its computed position and the pale circles showing roughly where each one lands on the working plane.

12 ft 10 ft 3 across × 3 deep · 4 ft × 3.3 ft apart · 2 ft from the end walls

Same room, different fixtures

If you have already chosen a fitting, read across from its lumen output.

Fixture outputRough equivalentFixtures neededSuggested grid
450 lm 40 W incandescent 164 × 4
650 lm 50 W incandescent 124 × 3
800 lm 60 W incandescent 93 × 3
1000 lm 75 W incandescent 93 × 3
1200 lm 100 W incandescent 63 × 2

Fewer, brighter fixtures give more contrast; more, dimmer fixtures give flatter, more even light. Both rows deliver the same total.

How the 9 was calculated

Target illuminance for a kitchen300 luxpublished range 300–500 lux
Floor area11.1 m²120 sq ft
Mounting height above the working plane5 ft8 ft ceiling, 3.0 ft working plane
Room index1.08(L × W) ÷ (Hm × (L + W))
Utilisation factor0.55from the room index, light surfaces
Maintenance factor0.8dirt and lamp depreciation
Lumens required7,655 lm300 × 11.1 ÷ (0.55 × 0.8)
Fixtures at 800 lm9delivering about 282 lux

Worktops are the critical surface, so a kitchen needs roughly double a living room. Under-cabinet lighting handles the task layer; ceiling fixtures handle the rest.

Other ceiling heights

CeilingFixturesGridSpacingMax spacing
8 ft93 × 34′ × 3.3′6.6′
9 ft124 × 33′ × 3.3′7.9′
10 ft124 × 33′ × 3.3′9.2′
12 ft124 × 33′ × 3.3′11.8′

Questions

How many recessed lights do I need for a 10x12 kitchen?

About 9 fixtures at 800 lumens each, arranged 3 across by 3 deep. That gives roughly 282 lux across 120 square feet, against a target of 300 lux for a kitchen.

How many lumens does a 10x12 kitchen need?

Roughly 7,655 lumens in total. That comes from 300 lux over 11.1 m², divided by a utilisation factor of 0.55 and a maintenance factor of 0.8 — the light that never reaches the working plane has to be paid for up front.

How far apart should the lights be in a 10x12 room?

4 ft apart along the 12 ft wall and 3.3 ft apart along the 10 ft wall, with the outer row about 2 ft in from the end walls — half a spacing. With a 8 ft ceiling the maximum sensible spacing is around 6.6 ft before the floor starts to show scallops.

Does the ceiling height change the answer?

Yes, in two ways. A higher ceiling spreads each fixture's light over a wider area, so fixtures can sit further apart — but it also drops the light level reaching the floor, so a taller room generally needs more total lumens. At 8 ft the room index works out at 1.08, giving a utilisation factor of 0.55.

Computed with the lumen method — see how it works and where it is weak. Planning guidance only, not an electrical design. Fixture counts are a starting point — follow your local wiring rules and use a licensed electrician for the installation.

One family of free data tools