LED High Bay Lighting for Warehouses: Height, Wattage and Spacing

A warehouse is not one lighting problem, it is two. The open floor where forklifts move, and the aisles between racking where people read labels at eye level. Light them as a single grid and one of the two will be wrong.

Mounting height decides the beam angle

This is the first decision and it is not negotiable. A narrow beam from a low mounting height gives you bright pools and dark gaps. A wide beam from a high roof wastes light on the walls.

• Up to 6 m — 120° wide beam
• 6 m to 9 m — 90° medium beam
• 9 m to 12 m — 60° narrow beam
• Above 12 m — 60° or tighter, and consider fewer, higher-wattage units

Wattage by height

Assuming a general storage target of roughly 150–200 lux on the floor, these are the wattages that usually land correctly.

• 5 m to 6 m roof — 100W per fitting
• 7 m to 8 m roof — 150W per fitting
• 9 m to 10 m roof — 200W per fitting
• 11 m and above — 300W to 400W per fitting

Spacing follows the beam

Use the same spacing-to-height thinking as roadway lighting. For general warehouse floor at a 90° beam, a spacing-to-height ratio near 1.5 gives good uniformity. So an 8 m roof suggests fittings roughly 12 m apart.

Tighten that ratio if you are lighting a picking operation where staff read small labels, and loosen it for bulk pallet storage where the forklift only needs to see the rack position.

Align to the aisles, not to the roof structure

The most common mistake is laying fittings out on a neat grid that matches the roof trusses, then installing racking underneath at a different angle. Every rack then casts its own shadow down the aisle.

• Run fittings down the centre line of each aisle wherever racking is fixed
• Use a narrower beam in aisles so light reaches the lower shelves
• Keep a wider beam over open floor, loading bays and the despatch area
• Light the loading bay apron separately — a flood light usually beats a high bay there

Before you order

• Confirm the roof height at the lowest point, not the ridge
• Mark where racking is fixed and where the floor stays open
• Check the supply — inbuilt surge protection matters on industrial estates
• Ask for the fin design; thermal management is what holds output past year two

Send a rough floor plan with roof height and rack positions and we will suggest a fitting count and layout alongside the quotation.