Lumens to Candela Calculator

Convert lumens to candela from the beam angle: cd = lumens / solid angle. Formula, worked example and a table. For millicandela, multiply by 1,000.

Estimate only. Not engineering or safety advice. Check the result against the applicable standard and the equipment data, and have a competent engineer review it before it is relied on. Terms of use.

Open in the calculator with these values

Formula

Worked example

1. Ω = 2π × (1 − cos(60° / 2)) = 0.84179 sr
2. I = Φ / Ω = 1,000 / 0.84179 = 1,187.949 cd

Typical values

Other inputs are the same as in the worked example above.

Assumptions

• Intensity is the same everywhere inside the cone
• No light outside the cone

Real beams are brightest on axis, so a data-sheet peak intensity gives more lumens than the beam really carries. Use the measured polar curve for accuracy.

Frequently asked questions

How do I convert Lumens to Candela?

Ω = 2π × (1 − cos(θ / 2)); Φ = I × Ω; I = Φ / Ω. Worked example: Luminous flux (lm) 1,000, full beam angle (°) 60 gives 1,187.95 cd.

What do I need to enter?

Enter luminous intensity (cd), luminous flux (lm) and full beam angle (°). Leave blank the value you want to find, and the form solves for it.

How do I convert millicandela?

One candela is 1,000 millicandela. Divide millicandela by 1,000 to get candela, then convert with the beam angle. The conversion is exact only for an even beam, so a measured polar curve is more accurate for a real LED.

How accurate are the results?

Every figure comes from the same tested engine as the Elecmetric calculators and is meant for estimating. Check design values against the standard and the equipment data you work to.

Related

Next steps in a design: Candela to LuxLumens to Watts
Opposite direction: Candela to Lumens
Also see: Lumens to Watts Watts to Lumens Lumens to Millicandela Millicandela to Lumens
Formula guides: Lighting Formulas: Lux, Lumens and CandelaPoint Illuminance Formulas
All 78 conversionsCandela and Lumens from Beam Angle in Elecmetric