Convert Foot-lamberts to Candelas per square inch
Convert Foot-lamberts (fL) to Candelas per square inch (cd/in²) instantly and accurately.
Conversion Formula
cd/in² = fL × 0.002210485321
About Foot-lamberts
The foot-lambert (fL) equals 1/(π×0.09290304) cd/m² ≈ 3.426 cd/m², the luminance of a perfect diffuse surface emitting 1 lumen per square foot. The SMPTE standard for cinema screen luminance is 14 fL (≈48 cd/m²); home projectors are rated 10-35 fL. Still standard in US cinema and theatre engineering. 1 fL = 1/(π×ft²) cd/m².
About Candelas per square inch
The candela per square inch (cd/in²) equals 1/0.00064516 cd/m² ≈ 1 550 cd/m². Used in US LED and CRT datasheets when citing luminance of small emitter areas. A high-brightness packaged LED chip in a focussed-beam configuration can reach 1-20 cd/in². 1 cd/in² = 1/(0.0254²) cd/m².
Quick Reference Table
| Foot-lamberts (fL) | Candelas per square inch (cd/in²) |
|---|---|
| 1 fL | 0.00221049 cd/in² |
| 2 fL | 0.00442097 cd/in² |
| 5 fL | 0.0110524 cd/in² |
| 10 fL | 0.0221049 cd/in² |
| 25 fL | 0.0552621 cd/in² |
| 50 fL | 0.110524 cd/in² |
| 100 fL | 0.221049 cd/in² |