Watts measure power, lumens measure light. Enter a bulb's wattage and type to see how many lumens it gives, how bright it is compared with an old incandescent, and how many LED watts produce the same light.
Last updated:
W
lm/W
Lumens on the box ÷ watts
h
Used for yearly energy use; leave empty to skip
Enter your values to see the result.
Advertisement
Advertisement
How to use the Watts to Lumens Converter
Enter the wattage printed on the bulb or fixture.
Pick the bulb type. Choose Custom and type the lumens-per-watt figure if you know it from the box.
Add the number of bulbs and hours per day to get total light and yearly energy use.
Read the lumens and the equivalent LED wattage, then check the 40–100 W table for replacements.
Watts to lumens equivalence chart
These are the brightness levels used on US bulb packaging. Find the incandescent wattage you are replacing, then read across for the lumens and the typical wattage of each newer technology.
Incandescent
Lumens (min.)
Halogen
CFL
LED
40 W
450 lm
29 W
9–11 W
4–6 W
60 W
800 lm
43 W
13–15 W
8–10 W
75 W
1,100 lm
53 W
18–20 W
11–13 W
100 W
1,600 lm
72 W
23–26 W
14–18 W
150 W
2,600 lm
—
38–42 W
23–28 W
LED ranges vary by brand and year; newer, high-efficiency LEDs sit at the low end of each range.
The watts to lumens formula
lumens = watts × luminous efficacy (lm/W)
Luminous efficacy is how much visible light a bulb produces for each watt of electricity. It is the only thing that links the two units, so a "watts to lumens" conversion always needs the bulb type.
LED: 9 W × 90 lm/W = 810 lm, a 60 W replacement.
CFL: 23 W × 60 lm/W = 1,380 lm, between a 75 W and a 100 W incandescent.
Incandescent: efficacy climbs from about 11 lm/W at 40 W to about 17 lm/W at 150 W, so this tool interpolates between the standard label points rather than using a single number.
Tips for choosing replacement bulbs
Shop by lumens, not watts. Two LEDs with the same wattage can differ in brightness by 30% or more.
Check color temperature. 2700 K looks like a warm incandescent, 3000 K like halogen, 4000–5000 K is cooler daylight-style light. Higher kelvin can feel brighter at the same lumens.
Mind fixture limits. A fixture rated "max 60 W" can safely take a 100 W-equivalent LED that draws about 15 W, because the limit is about heat, not light.
Dimmers: use LEDs labeled dimmable; older dimmers may need an LED-compatible replacement.
Frequently asked questions
How many lumens is 60 watts?
A standard 60 W incandescent bulb gives about 800 lumens. The same 800 lumens comes from roughly 43 W of halogen, 13–15 W of CFL or 8–10 W of LED, which is why LED packages say "60 W equivalent".
Is there one formula to convert watts to lumens?
Lumens = watts × luminous efficacy (lumens per watt). Efficacy depends on the technology: about 11–17 lm/W for incandescent, 16–22 for halogen, around 60 for CFL and roughly 75–120 for modern LEDs, so you need to know the bulb type.
How many lumens is a 100 watt equivalent LED?
About 1,600 lumens. That is the light of a 100 W incandescent bulb, and most LEDs reach it with roughly 14–18 W.
Why does a higher-watt incandescent bulb give more lumens per watt?
A hotter filament radiates a larger share of its energy as visible light, so 100 W bulbs run at about 16 lm/W while 40 W bulbs manage about 11 lm/W. This converter follows those standard label values instead of using one flat number.
How do I find my bulb's exact lumens?
Look at the packaging or the base of the bulb. In the US the Lighting Facts label shows brightness in lumens and the wattage; dividing lumens by watts gives the efficacy you can enter in Custom mode.
Do lumens tell me how bright a room will be?
Lumens are the total light a bulb emits. How bright a room feels also depends on its size, wall colors and fixture direction. Use a lumens-per-room calculator for that, then this tool to pick bulbs.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.