Candela ⇄ Lumen Converter
Convert luminous intensity in candela to luminous flux in lumens (and back) for a given beam angle, free online.
About this calculator
Luminous flux Φ = I × Ω, where the solid angle of a cone with full beam angle θ is Ω = 2π(1 − cos(θ/2)) steradians. A 360° spherical source of 1 cd emits 4π ≈ 12.57 lm. Use the beam angle printed on spotlight bulbs.