CRI, the Color Rendering Index, rates how accurately a light source shows colors compared with natural light, on a scale up to 100. Higher CRI means truer-looking colors.
Reading the scale
A CRI of 90 or above is excellent and suited to art, retail, and medical work. The 80s are good for offices and homes. Below 80, colors start to look noticeably off.
Why R9 matters
General CRI can hide weak deep-red rendering. The separate R9 value covers strong reds, which is why skin tones and food look best under sources with both high CRI and high R9.
| CRI range | Quality |
|---|---|
| 90 to 100 | Excellent |
| 80 to 89 | Good |
| 70 to 79 | Fair |
| Below 70 | Poor |
See the CRI Reference Chart and the CRI to TM-30 Converter.
How to use CRI when choosing lights
CRI scores from 0 to 100, comparing how faithfully a source renders standard color samples against a reference. 80+ is fine for most homes and offices; 90+ is recommended where color accuracy matters — retail, art, makeup, kitchens, and photography. A common weak point is deep red (the R9 value), which the headline CRI can hide, so check R9 separately when reds matter. CRI is independent of color temperature: a 2700K and a 5000K lamp can both be 90 CRI. And it says nothing about brightness or efficiency, so weigh it alongside lumens and efficacy when comparing products.
Is higher CRI always better? For color-critical work yes, but very high CRI can slightly reduce efficiency, so 80–90 is a sensible balance for general spaces.