Color Temperature Calculator

Calculate color temperature conversions, CIE xy CCT, and Kelvin to RGB/hex values for lighting filters and color correction with presets.

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• Wavelength Color Calculator

Color Temperature Formula

The following formula (Wien’s displacement law) is used to estimate the temperature of a blackbody from its peak wavelength (λ_max).

T (K) = (2.897771955 × 10^6 nm·K) / λ_max (nm).  

Variables:

• T is the (blackbody) color temperature in Kelvin (K)
• λ_max is the peak wavelength in nanometers (nm)

To calculate the color temperature from a peak wavelength in nanometers, divide 2,897,771.955 by λ_max (nm). This is a blackbody approximation; for real light sources, “color temperature” often refers to correlated color temperature (CCT), which generally cannot be determined from a single wavelength alone.

What is Color Temperature?

Color temperature (often reported as correlated color temperature, or CCT) is a characteristic of visible light that describes the hue of a light source. It is measured in Kelvin (K) and is used to describe the warmth or coolness of a light source. Lower color temperatures (around 2000-3000K) produce a warm, yellowish light, while higher color temperatures (above 5000K) produce a cool, bluish light. Color temperature is an important factor in photography, videography, and lighting design, as it affects the mood and appearance of a scene.

How to Calculate Color Temperature?

The following steps outline how to calculate the Color Temperature.

1. First, determine the peak wavelength of the light (λ_max).
2. Next, use the formula T = (2.897771955 × 10^6) / λ_max (with λ_max in nm) to calculate the color temperature in Kelvin.
3. Finally, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Peak Wavelength (λ_max) = 500 nm

Calculate the color temperature using the formula T = (2.897771955 × 10^6) / λ_max.