Lumens to Watts Converter (LED vs Traditional Bulb)
Convert a brightness value in lumens to the equivalent wattage for LED, CFL, and incandescent (traditional) bulbs using standard luminous efficacy values.
Formula
Watts = Lumens ÷ Luminous Efficacy (lm/W)
| Bulb Type | Typical Efficacy | Range |
|---|---|---|
| LED | 90 lm/W | 80–100 lm/W |
| CFL | 60 lm/W | 50–70 lm/W |
| Halogen | 20 lm/W | 16–24 lm/W |
| Incandescent | 13 lm/W | 10–17 lm/W |
Example: 800 lm LED → 800 ÷ 90 ≈ 8.9 W | 800 lm Incandescent → 800 ÷ 13 ≈ 61.5 W
Assumptions & References
- Luminous efficacy values are typical mid-range figures; actual bulb performance varies by manufacturer and model.
- LED efficacy range (80–100 lm/W) per the U.S. Department of Energy (DOE) Solid-State Lighting program.
- CFL efficacy range (50–70 lm/W) per ENERGY STAR CFL specifications.
- Incandescent efficacy range (10–17 lm/W) per IEC 60064 standard lamp data.
- Halogen efficacy range (16–24 lm/W) per IEC 60357 standard.
- Annual cost calculation assumes 3 hours/day usage and a U.S. average electricity rate of $0.13/kWh (EIA, 2023).
- A standard 60 W incandescent bulb produces approximately 800 lm; a 100 W bulb produces approximately 1,600 lm.
- This tool is intended for estimation purposes; always check the bulb's packaging for exact lumen and watt ratings.