Lumen (unit)

The lumen is the SI unit of luminous flux, which quantifies the perceived power of visible light emitted by a source. Luminous flux differs from power, which encompasses all electromagnetic waves emitted, including non-visible ones such as thermal radiation (infrared). By contrast, luminous flux is weighted according to a model of the human eye's sensitivity to various wavelengths; this weighting is standardized by the CIE and ISO.

Back to Light & Color →

Source: Wikipedia · Image: Wikimedia Commons · CC BY 4.0

LEDBOOM

Bright ideas in LED — bulbs and fixtures, strips and smart lighting, design and efficiency, and the tools that light every room right.

Get new guides by emailOccasional emails. No spam. Unsubscribe anytime.

InformationAbout Contact Privacy Policy Terms of Service Disclaimer Affiliate Disclosure Cookie Policy

Every image, fact, and figure is drawn from Wikipedia and Wikimedia Commons, used under public-domain and Creative Commons licenses. No content is AI-generated.