LED Wattage Selection Guide

How many watts do you need? Find the right LED wattage by ceiling height, mounting height, and application type.

High Bay LED — By Ceiling Height

For warehouses, manufacturing, gyms, retail big-box, and indoor sports facilities.

Ceiling HeightTypical ApplicationRecommended WattageLumensSpacingFixture Type
15-20 ftSmall warehouse, retail100W15,00015-20 ftUFO High Bay
20-25 ftMedium warehouse, gym150W24,00020-25 ftUFO High Bay
25-30 ftLarge warehouse, manufacturing200W30,00020-25 ftUFO High Bay
30-40 ftDistribution center, arena240W36,00025-30 ftUFO High Bay
20-30 ftRacking aisles (narrow)165W24,00015-20 ftLinear High Bay
25-40 ftAssembly line (wide aisle)220W33,00020-25 ftLinear High Bay

Based on 50 foot-candle target (general warehouse). Higher-precision tasks may require additional fixtures. Use LightSpec AI for exact calculations.

Area Light / Shoebox LED — By Pole Height

For parking lots, pathways, campuses, and outdoor commercial areas.

Pole HeightApplicationRecommended WattageLumensPole SpacingTarget FC
15-20 ftPathways, walkways75-100W10,000-15,00040-60 ft1-2 fc
20-25 ftResidential parking150W22,00060-80 ft1-2 fc
25-30 ftCommercial parking200W30,00070-90 ft2-5 fc
30-35 ftRetail/hospital parking300W45,00080-100 ft3-5 fc
30-40 ftCar dealership320W48,00070-90 ft5-10 fc

FC = foot-candles per IES RP-20. Spacing assumes Type III or V distribution. Actual layout depends on lot geometry.

Wall Pack LED — By Mounting Height

For building perimeters, entrances, loading docks, walkways, and security lighting.

Mounting HeightApplicationRecommended WattageLumensCoverage Area
8-10 ftDoorways, entries20-30W2,400-3,60015-20 ft radius
10-12 ftLoading docks, walkways40-60W5,000-8,00020-30 ft radius
12-16 ftBuilding perimeter80-100W10,000-13,00030-40 ft radius
16-20 ftLarge facades, warehouses120W16,00040-50 ft radius

Quick Calculation Formula

Number of Fixtures = (Area × Target FC) ÷ (Lumens per Fixture × CU × LLF)

  • Area: Square footage of the space
  • Target FC: Foot-candles required (see FC Calculator)
  • CU: Coefficient of Utilization (typically 0.6-0.8)
  • LLF: Light Loss Factor (typically 0.85-0.95 for LED)

For precise calculations with real photometric data, use our free LightSpec AI tool.

Get Exact Fixture Counts for Your Space

LightSpec AI calculates precise fixture recommendations using real photometric data — not estimates.

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Frequently Asked Questions

How many watts LED for a 20-foot ceiling?

100-150W LED high bays. A 150W fixture at 150 lm/W produces 22,500 lumens, sufficient for 30 FC at 20 ft mounting height.

What wattage LED replaces 400W metal halide?

150W LED. The MH draws 460W with ballast, so you save 67% energy while maintaining light levels.

What wattage LED for a parking lot on 25 ft poles?

150-200W LED area lights. A 200W fixture covers ~80×80 ft at 2 FC average per IES RP-20.

How many watts per square foot for warehouse LED?

0.5-0.7 W/ft² for 30 FC. A 10,000 sq ft warehouse needs ~5,000-7,000W total LED.