Lighting Plan Calculator

Estimate how many light fittings a room needs from its area and a target illuminance, and see the total lumens and watts. Choose the room use to set a target lux, then enter the room area and the output of each fitting. This is an approximate estimate for planning, not a lighting design; real levels depend on ceiling height, wall colour and layout. All processing runs locally in your browser. Your data is not uploaded to any server. 100% Local

How to Use the Lighting Plan Calculator

Choose your units and the room use (which sets a target illuminance in lux), then enter the area and the lumens and watts of each fitting. Press Calculate lights to see how many fittings to plan and the total light output and power.

What it accounts for

• Required lumens are the area multiplied by the target illuminance.
• The fitting count is the required lumens divided by the output of one fitting, rounded up.
• Total watts are the count multiplied by the power of one fitting.

Getting a better number

Dark walls, high ceilings and heavy shading all reduce the light that reaches the room, so allow more fittings. Add separate task lighting for worktops, desks and mirrors rather than relying on the general level alone.

Features

• Fitting count from area and target lux
• Total lumens and total watts
• Target illuminance by room use
• All processing runs locally in your browser. Your data is not uploaded to any server.
• Results are approximate estimates; check the fitting datasheet and consider a professional lighting plan.

Use the result as a starting point, then adjust for the room's geometry and the mood you want.

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