Light Unit Converter
Free online light unit converter for instant light and illumination conversions.
Perfect for photography, lighting design, and scientific applications.
Last updated · How we build & check our tools
Frequently Asked Questions
Common questions about the Light Unit Converter
Luminous flux: lumens (total light). Luminous intensity: candela (directional). Illuminance: lux or foot-candles (light on surface). Luminance: cd/m² or nits (surface brightness).
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Sources & References
International System of Units (SI): luminous intensity and illuminance
Luminous intensity and illuminance is measured in the candela (cd) and lux (lx). Conversions between SI and other units use exact, internationally agreed factors maintained by NIST.
International System of Units (SI)
Authoritative definitions for luminous intensity and illuminance, from the BIPM SI Brochure (9th edition), the defining reference for the SI.