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LuxPlan
784 sq ft · 300 lux target

28×28 kitchen:
49 lights

49 fixtures A 28×28 ft kitchen (784 sq ft) needs approximately 49 recessed lights at 800 lumens each — about 37,089 lumens in total — laid out 7 across by 7 deep.

Space them 4 ft apart along the 28 ft wall and 4 ft apart along the 28 ft wall, starting 2 ft from the end walls.

Fixtures49at 800 lm each
Total lumens37,089to hit 300 lux
Spacing4′× 4′ 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.

28 ft 28 ft 7 across × 7 deep · 4 ft × 4 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 8282 × 1
650 lm 50 W incandescent 567 × 8
800 lm 60 W incandescent 497 × 7
1000 lm 75 W incandescent 366 × 6
1200 lm 100 W incandescent 305 × 6

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

How the 49 was calculated

Target illuminance for a kitchen300 luxpublished range 300–500 lux
Floor area72.8 m²784 sq ft
Mounting height above the working plane5 ft8 ft ceiling, 3.0 ft working plane
Room index2.77(L × W) ÷ (Hm × (L + W))
Utilisation factor0.74from the room index, light surfaces
Maintenance factor0.8dirt and lamp depreciation
Lumens required37,089 lm300 × 72.8 ÷ (0.74 × 0.8)
Fixtures at 800 lm49delivering about 317 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 ft497 × 74′ × 4′6.6′
9 ft497 × 74′ × 4′7.9′
10 ft497 × 74′ × 4′9.2′
12 ft567 × 84′ × 3.5′11.8′

Questions

How many recessed lights do I need for a 28x28 kitchen?

About 49 fixtures at 800 lumens each, arranged 7 across by 7 deep. That gives roughly 317 lux across 784 square feet, against a target of 300 lux for a kitchen.

How many lumens does a 28x28 kitchen need?

Roughly 37,089 lumens in total. That comes from 300 lux over 72.8 m², divided by a utilisation factor of 0.74 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 28x28 room?

4 ft apart along the 28 ft wall and 4 ft apart along the 28 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 2.77, giving a utilisation factor of 0.74.

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.

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