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Luminance ConverterConvert between candela/m², nits, lamberts, and foot-lamberts.

Luminance Converter illustration
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Luminance Converter

Convert between candela/m², nits, lamberts, and foot-lamberts.

How to Use
1

Enter luminance

Type the luminance value.

2

Select units

Choose source and target luminance units.

3

Get the result

Converted luminance appears instantly.

What Is Luminance Converter?

A luminance converter translates between units measuring the brightness of a surface as perceived by the human eye. Candela per square meter (cd/m²) is the SI unit, also known as the "nit" in display technology. Lamberts and foot-lamberts are older units still used in cinema projection and some lighting specifications. Luminance is crucial for display engineering (phone screens, TVs, monitors), cinema projection, and architectural lighting design.

Why Use Our Luminance Converter?

  • Essential for display technology and cinema projection.
  • Converts between modern (nit) and legacy (lambert, fL) units.
  • Quick reference for typical luminance values.
  • Real-time bidirectional conversion.

Common Use Cases

Display Engineering

Specify and compare screen brightness in nits, cd/m², and foot-lamberts.

Cinema Projection

Convert cinema screen brightness specifications between fL and nits.

Lighting Design

Calculate surface luminance for architectural lighting.

Photography

Understand exposure in terms of scene luminance.

Technical Guide

Luminance measures luminous intensity per unit area of a surface. Units: • 1 cd/m² = 1 nit (the standard for display brightness specs) • 1 lambert = 10,000/π ≈ 3,183 cd/m² • 1 foot-lambert = 1/π × 10.764 ≈ 3.426 cd/m² Typical luminance values: • Smartphone screen: 400-1,000 nits • HDR TV peak: 1,000-4,000 nits • Cinema screen (SMPTE standard): 14 fL ≈ 48 nits • Dolby Cinema: 31 fL ≈ 106 nits • Sunlit snow: ~30,000 nits • Full moon surface: ~2,500 nits

Tips & Best Practices

  • 1
    Nits and cd/m² are the same thing — "nit" is just the informal name.
  • 2
    SMPTE cinema standard is 14 fL (48 nits); Dolby Cinema targets 31 fL (106 nits).
  • 3
    HDR displays need at least 1,000 nits peak brightness.
  • 4
    Outdoor-readable displays typically need 500+ nits.

Related Tools

Frequently Asked Questions

QWhat is a nit?
A nit is an informal name for candela per square meter (cd/m²), the SI unit of luminance. It is the standard unit for specifying display brightness.
QHow bright should a phone screen be?
Typical phones range from 400-1,000 nits. High-end phones may reach 2,000+ nits for outdoor visibility.
QWhat is a foot-lambert?
A foot-lambert (fL) is a non-SI luminance unit equal to about 3.426 cd/m². It is still used in the US cinema industry.
QHow many nits for HDR?
HDR content typically requires at least 1,000 nits peak brightness, with some standards requiring 4,000+ nits.

About Luminance Converter

Luminance Converter is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.