Convert Picolumens to Watts (at 555 nm)
Convert Picolumens (plm) to Watts (at 555 nm) (W₅₅₅) instantly and accurately.
Conversion Formula
W₅₅₅ = plm × 1.464128843e-15
About Picolumens
The picolumen (plm) equals 10⁻¹² lm. A sub-unit used only in precision optical metrology and photomultiplier calibration chains. Equivalent to the photometric output of a 555 nm monochromatic source radiating approximately 1.46 fW of radiant power. Below the sensitivity threshold of most photometric instruments without special cooling. 1 plm = 10⁻¹² lm.
About Watts (at 555 nm)
The watt at 555 nm equals 683 lm exactly, by the 2019 SI definition fixing the luminous efficacy constant K_cd = 683 lm/W at 540 THz (≈ 555 nm, the peak of the photopic eye-sensitivity curve V(λ)). Used in LED optical design and photonics research to convert between radiometric power and photometric flux at peak eye sensitivity. 1 W₅₅₅ = 683 lm.
Quick Reference Table
| Picolumens (plm) | Watts (at 555 nm) (W₅₅₅) |
|---|---|
| 1 plm | 1.464 × 10-15 W₅₅₅ |
| 2 plm | 2.928 × 10-15 W₅₅₅ |
| 5 plm | 7.321 × 10-15 W₅₅₅ |
| 10 plm | 1.464 × 10-14 W₅₅₅ |
| 25 plm | 3.66 × 10-14 W₅₅₅ |
| 50 plm | 7.321 × 10-14 W₅₅₅ |
| 100 plm | 1.464 × 10-13 W₅₅₅ |