A nit is an informal name for candela per square meter (cd/m²). It is the standard unit for measuring screen and display brightness.

How bright is 1,000 nits?

1,000 nits (cd/m²) is typical for outdoor-viewable smartphone displays. An average office monitor is 200–400 nits. The sun's surface is about 1.6 billion nits.

What is a foot-lambert?

A foot-lambert (fL) is a US unit of luminance equal to 3.4263 cd/m². Cinema projectors typically aim for 14–16 foot-lamberts on the screen.

Luminance Converter

How to Use the Luminance Converter

Enter the luminance value in the Value field and select the unit you are converting from. All equivalents update instantly.

Luminance Units Explained

Luminance measures the intensity of light emitted or reflected from a surface per unit area, as perceived by the eye. It describes how bright a surface appears. The SI unit is the candela per square meter (cd/m²).

Candela/m² (cd/m²) — SI unit of luminance. Also called the nit.
Nit — informal name for cd/m². 1 nit = 1 cd/m². Used for display specifications (TVs, monitors, phones).
Foot-lambert (fL) — 3.4263 cd/m². US unit used for cinema screens and projection systems.
Lambert (L) — CGS unit: 1 L = 10,000/π cd/m² ≈ 3,183 cd/m².
Stilb (sb) — CGS unit: 1 sb = 1 cd/cm² = 10,000 cd/m². Used historically in photometry.
Apostilb (asb) — 1/π cd/m² ≈ 0.3183 cd/m². Used in projection and retroreflection standards.

Typical Luminance Values

Office monitor: 200–400 nit | Smartphone outdoor: 800–2,000 nit | Clear sky: ~8,000 nit | Sun: ~1.6 billion nit

Worked Examples

OLED TV: 800 nit to foot-lambert

800 ÷ 3.42626 = 233.5 fL. Premium OLED TVs reach 500–1,000 nits peak brightness.

Cinema screen: 14 fL to cd/m²

14 × 3.42626 = 47.97 cd/m². The SMPTE standard for cinema projection is 14 fL.

Laptop display: 300 nit to apostilb

300 ÷ 0.31831 = 942 asb.

Industrial monitor: 1,500 nit to stilb

1,500 ÷ 10,000 = 0.15 sb = 0.15 cd/cm².

Frequently Asked Questions

What is the difference between luminance and illuminance?

Luminance (cd/m²) measures how much light a surface emits or reflects toward your eye — the perceived brightness of a surface. Illuminance (lux, lm/m²) measures how much light falls on a surface.

How many nits is a good TV?

For SDR content, 300–500 nits is good. For HDR, 600–1,000 nits is standard, and 1,000+ nits is premium. The HDR10 specification targets 1,000 nits peak.

What is peak luminance vs. sustained luminance?

Peak luminance is the maximum brightness a display can reach for short periods (small bright areas). Sustained luminance is the stable brightness over a large area or long duration. Peak is always higher than sustained.