Room Lighting (Lux) Calculator
Room size and target lux → total lumens and number of fittings, with sourced reference lux values.
Open the toolFree lighting calculators
Calculators for planning LED and other lighting that run entirely in your browser. Each one only uses the numbers you enter and shows its formula, units, sources and limits.
Watts to Lumens Converter
Watts ↔ lumens for LED, halogen and incandescent bulbs, with the efficacy values and sources shown.
Open the toolLED Strip Power Supply Calculator
W per metre × length → total watts, amps and a power-supply rating with headroom.
Open the toolBeam Angle and Spot Size Calculator
Mounting height and beam angle → spot diameter, or the beam angle for a wanted spot size.
Open the toolBattery Runtime Calculator for LED Lights
Battery capacity and power draw → estimated runtime, with usable capacity and converter losses.
Open the toolFor background reading, see the articles section.