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LuxPlan
720 sq ft · 150 lux target

24×30 garage:
24 lights

24 fixtures A 24×30 ft garage (720 sq ft) needs approximately 24 recessed lights at 800 lumens each — about 19,597 lumens in total — laid out 6 across by 4 deep.

Space them 5 ft apart along the 30 ft wall and 6 ft apart along the 24 ft wall, starting 2.5 ft from the end walls.

Fixtures24at 800 lm each
Total lumens19,597to hit 150 lux
Spacing5′× 6′ apart
Wall offset2.5′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.

30 ft 24 ft 6 across × 4 deep · 5 ft × 6 ft apart · 2.5 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 459 × 5
650 lm 50 W incandescent 306 × 5
800 lm 60 W incandescent 246 × 4
1000 lm 75 W incandescent 205 × 4
1200 lm 100 W incandescent 164 × 4

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

How the 24 was calculated

Target illuminance for a garage150 luxpublished range 150–300 lux
Floor area66.9 m²720 sq ft
Mounting height above the working plane8 ft8 ft ceiling, measured to the floor
Room index1.67(L × W) ÷ (Hm × (L + W))
Utilisation factor0.64from the room index, light surfaces
Maintenance factor0.8dirt and lamp depreciation
Lumens required19,597 lm150 × 66.9 ÷ (0.64 × 0.8)
Fixtures at 800 lm24delivering about 147 lux

A plain storage garage sits at the low end; if you actually work on things in there, design for the top of the range or higher.

Other ceiling heights

CeilingFixturesGridSpacingMax spacing
8 ft246 × 45′ × 6′10.4′
9 ft255 × 56′ × 4.8′11.7′
10 ft255 × 56′ × 4.8′13′
12 ft306 × 55′ × 4.8′15.6′

Questions

How many recessed lights do I need for a 24x30 garage?

About 24 fixtures at 800 lumens each, arranged 6 across by 4 deep. That gives roughly 147 lux across 720 square feet, against a target of 150 lux for a garage.

How many lumens does a 24x30 garage need?

Roughly 19,597 lumens in total. That comes from 150 lux over 66.9 m², divided by a utilisation factor of 0.64 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 24x30 room?

5 ft apart along the 30 ft wall and 6 ft apart along the 24 ft wall, with the outer row about 2.5 ft in from the end walls — half a spacing. With a 8 ft ceiling the maximum sensible spacing is around 10.4 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 1.67, giving a utilisation factor of 0.64.

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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