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LuxPlan
676 sq ft · 400 lux target

26×26 workshop:
56 lights

56 fixtures A 26×26 ft workshop (676 sq ft) needs approximately 56 recessed lights at 800 lumens each — about 43,340 lumens in total — laid out 7 across by 8 deep.

Space them 3.7 ft apart along the 26 ft wall and 3.3 ft apart along the 26 ft wall, starting 1.9 ft from the end walls.

Fixtures56at 800 lm each
Total lumens43,340to hit 400 lux
Spacing3.7′× 3.3′ apart
Wall offset1.9′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.

26 ft 26 ft 7 across × 8 deep · 3.7 ft × 3.3 ft apart · 1.9 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 9696 × 1
650 lm 50 W incandescent 7010 × 7
800 lm 60 W incandescent 567 × 8
1000 lm 75 W incandescent 426 × 7
1200 lm 100 W incandescent 366 × 6

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

How the 56 was calculated

Target illuminance for a workshop400 luxpublished range 500–750 lux
Floor area62.8 m²676 sq ft
Mounting height above the working plane5 ft8 ft ceiling, 3.0 ft working plane
Room index2.58(L × W) ÷ (Hm × (L + W))
Utilisation factor0.72from the room index, light surfaces
Maintenance factor0.8dirt and lamp depreciation
Lumens required43,340 lm400 × 62.8 ÷ (0.72 × 0.8)
Fixtures at 800 lm56delivering about 413 lux

The highest requirement here. The ceiling is sized to 400 lux with task lighting assumed over the bench — machine and detail work needs both quantity and good colour rendering.

Other ceiling heights

CeilingFixturesGridSpacingMax spacing
8 ft567 × 83.7′ × 3.3′6.6′
9 ft567 × 83.7′ × 3.3′7.9′
10 ft6010 × 62.6′ × 4.3′9.2′
12 ft648 × 83.3′ × 3.3′11.8′

Questions

How many recessed lights do I need for a 26x26 workshop?

About 56 fixtures at 800 lumens each, arranged 7 across by 8 deep. That gives roughly 413 lux across 676 square feet, against a target of 400 lux for a workshop.

How many lumens does a 26x26 workshop need?

Roughly 43,340 lumens in total. That comes from 400 lux over 62.8 m², divided by a utilisation factor of 0.72 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 26x26 room?

3.7 ft apart along the 26 ft wall and 3.3 ft apart along the 26 ft wall, with the outer row about 1.9 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 2.58, giving a utilisation factor of 0.72.

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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