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LuxPlan
256 sq ft · 150 lux target

16×16 dining room:
9 lights

9 fixtures A 16×16 ft dining room (256 sq ft) needs approximately 9 recessed lights at 800 lumens each — about 7,298 lumens in total — laid out 3 across by 3 deep.

Space them 5.3 ft apart along the 16 ft wall and 5.3 ft apart along the 16 ft wall, starting 2.7 ft from the end walls.

Fixtures9at 800 lm each
Total lumens7,298to hit 150 lux
Spacing5.3′× 5.3′ apart
Wall offset2.7′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.

16 ft 16 ft 3 across × 3 deep · 5.3 ft × 5.3 ft apart · 2.7 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 123 × 4
800 lm 60 W incandescent 93 × 3
1000 lm 75 W incandescent 93 × 3
1200 lm 100 W incandescent 62 × 3

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 dining room150 luxpublished range 150–300 lux
Floor area23.8 m²256 sq ft
Mounting height above the working plane5.5 ft8 ft ceiling, 2.5 ft working plane
Room index1.44(L × W) ÷ (Hm × (L + W))
Utilisation factor0.61from the room index, light surfaces
Maintenance factor0.8dirt and lamp depreciation
Lumens required7,298 lm150 × 23.8 ÷ (0.61 × 0.8)
Fixtures at 800 lm9delivering about 148 lux

Usually a pendant over the table plus a modest ambient layer. The figure here covers the ambient layer only.

Other ceiling heights

CeilingFixturesGridSpacingMax spacing
8 ft93 × 35.3′ × 5.3′7.2′
9 ft93 × 35.3′ × 5.3′8.5′
10 ft93 × 35.3′ × 5.3′9.8′
12 ft123 × 45.3′ × 4′12.4′

Questions

How many recessed lights do I need for a 16x16 dining room?

About 9 fixtures at 800 lumens each, arranged 3 across by 3 deep. That gives roughly 148 lux across 256 square feet, against a target of 150 lux for a dining room.

How many lumens does a 16x16 dining room need?

Roughly 7,298 lumens in total. That comes from 150 lux over 23.8 m², divided by a utilisation factor of 0.61 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 16x16 room?

5.3 ft apart along the 16 ft wall and 5.3 ft apart along the 16 ft wall, with the outer row about 2.7 ft in from the end walls — half a spacing. With a 8 ft ceiling the maximum sensible spacing is around 7.2 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 1.44, giving a utilisation factor of 0.61.

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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