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Converters

Luminous Flux Converter

Convert luminous flux accurately between lumens, microlumens, millilumens, kilolumens, megalumens, and candela steradians using exact SI relationships.

Example: a lamp produces 1,500 lumens of luminous flux. How many kilolumens is that?
Result 1.5 klm 1,500 lm = 1.5 klm
One-unit equivalent 1 lm = 0.001 klm A quick way to understand the relationship between the two units.

✓ Conversion factors match data and definitions from the National Institute of Standards and Technology (NIST)

How is the conversion calculated? The lumen is the SI unit of luminous flux and is exactly equal to candela steradian. Micro, milli, kilo and mega are exact decimal SI prefixes.

This calculation runs in your browser. Your values are not sent to our server.

How it works

  1. Enter a luminous-flux value, then choose the current and target units.
  2. Example: 1,500 lumens equals exactly 1.5 kilolumens.
  3. The lumen is the SI unit of luminous flux, and NIST gives the exact unit relationship lm = cd·sr.
  4. Micro, milli, kilo and mega use the exact SI decimal prefixes 10⁻⁶, 10⁻³, 10³ and 10⁶.
  5. Candela steradian is not a different photometric quantity here; it is exactly equivalent to the lumen as a unit of luminous flux.
  6. This tool converts luminous flux only. It does not mix flux with illuminance in lux or luminance in cd/m².

FAQ

How many lumens are in 1 kilolumen?

1 kilolumen equals exactly 1,000 lumens.

How many lumens are in 1 megalumen?

1 megalumen equals exactly 1,000,000 lumens.

Is 1 lumen equal to 1 candela steradian?

Yes. In SI, 1 lm = 1 cd·sr exactly.

Is a lumen the same as a lux?

No. Lumen measures total luminous flux, while lux measures illuminance and equals one lumen per square metre.

Can luminous flux be negative?

Not in this converter. A luminous-flux magnitude is treated as non-negative, so negative inputs are rejected.

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