Colour Temperature & CRI Calculator

Convert between Kelvin and Mired, calculate the correction gel needed to shift from one colour temperature to another, and look up typical CRI values for common lamp types.

Kelvin ↔ Mired Converter

Colour Temperature

Mired (Micro Reciprocal Degrees)

MRD

1800 K 10000 K

CT Shift & Gel Finder

Enter a source and target colour temperature to calculate the mired shift, then see the closest correction gels.

Source CT

Target CT

Required Mired Shift

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Common scenarios

Closest matching gels

Code	Name	Mired Shift	Transmission	Difference

CRI Reference by Lamp Type

Typical CRI (Colour Rendering Index) values for common light sources used in theatre and entertainment.

Light Source	CT Range (K)	Typical CRI	Rating

Standard Correction Gel Reference

All CT correction gels from Lee Filters and Rosco, sorted by mired shift. Data sourced from manufacturer-published specification sheets.

Code	Name	Mired Shift	Transmission	Notes

Data compiled from Lee Filters and Rosco published specification sheets.