Quick reference table
Common luminous flux conversions
| From | To |
|---|---|
| 1 klm | 1,000 lm |
| 1 lm | 1 mlm |
| 1 W (555 nm) | 683.002 lm |
| 1 cd·sr | 1 lm |
How to convert luminous flux
Luminous flux is the total visible light a source emits, measured in lumens. Bulbs and projectors are rated in lumens. The watt value shown here is light at its most visible wavelength (555 nm), not electrical power.
Every luminous flux unit is a fixed multiple of one base unit, the lm. To convert a value, multiply it by the size of the starting unit and divide by the size of the target unit. For example, to convert klm to lm, multiply by 1,000. To go the other way, divide by 1,000.
The converter above does this for you and shows the exact formula under the result.
Worked examples
Kilolumens to Lumens
| Kilolumens (klm) | Lumens (lm) |
|---|---|
| 1 klm | 1,000 lm |
| 2 klm | 2,000 lm |
| 5 klm | 5,000 lm |
| 10 klm | 10,000 lm |
| 25 klm | 25,000 lm |
| 50 klm | 50,000 lm |
| 100 klm | 100,000 lm |
| 1,000 klm | 1,000,000 lm |
Lumens to Millilumens
| Lumens (lm) | Millilumens (mlm) |
|---|---|
| 1 lm | 1 mlm |
| 2 lm | 2 mlm |
| 5 lm | 5 mlm |
| 10 lm | 1 mlm |
| 25 lm | 25 mlm |
| 50 lm | 5 mlm |
| 100 lm | 1 mlm |
| 1,000 lm | 1 mlm |
Luminous flux units explained
| Unit | Symbol | Equals |
|---|---|---|
| Lumens | lm | 1 lm = 1 lm |
| Millilumens | mlm | 1 mlm = 0.001 lm |
| Kilolumens | klm | 1 klm = 1,000 lm |
| Candela-steradians | cd·sr | 1 cd·sr = 1 lm |
| Watts of light at 555 nm | W (555 nm) | 1 W (555 nm) = 683.002 lm |
Popular conversions: lumens to watts, lm to cd.
Frequently asked questions
How many lumens is 1 watt of light?
At the most visible wavelength (555 nm), one watt of light is 683 lumens. Light bulbs convert electricity to light less efficiently, so a 10 W LED giving 1,000 lm is a typical value.
How do I convert klm to lm?
Multiply the value in klm by 1,000 to get lm. For example, 10 klm = 10,000 lm.
How many lm is 1 klm?
1 klm = 1,000 lm, and 1 lm = 0.001 klm.
Does this luminous flux converter work offline?
Yes. After the page has loaded once, all calculations run in your browser, so it keeps working without an internet connection.