Projector brightness calculator
Will your projector be bright enough? Enter lumens, screen size and gain to get on-screen brightness in foot-lamberts and nits, with a verdict for dark and lit rooms.
A 2,000-lumen projector on a 100-inch 1.0-gain screen gives about 67.4 foot-lamberts (231 nits) — around the cinema target of 16 fL, so it is great in a dark room but dim in a lit one. Enter your numbers below for foot-lamberts, nits, and a verdict.
On-screen brightness by lumens (100-inch, 1.0 gain)
| Lumens | Foot-lamberts | Verdict |
|---|---|---|
| 1,000 | 33.7 | Good for a dark room |
| 1,500 | 50.6 | Handles some ambient light |
| 2,000 | 67.4 | Handles some ambient light |
| 3,000 | 101.1 | Very bright |
| 4,000 | 134.8 | Very bright |
How on-screen brightness works
Lumens measure the projector’s total light output; what your eyes see is brightness per area, in foot-lamberts (fL) or nits. fL = lumens × screen gain ÷ screen area (sq ft), and 1 fL ≈ 3.43 nits. The SMPTE cinema target is about 16 fL in a dark room; 30+ fL suits some ambient light and 50+ fL fights a bright room. A bigger screen spreads the same lumens thinner, so brightness drops fast as size grows — and a higher-gain screen raises it back up.
Want the reverse — how many lumens you need? Use the lumens calculator. →
Is it bright enough?
67.4
Foot-lamberts
231
Nits (cd/m²)
Frequently asked questions
Updated