Calculate CIE 1931 xy Coordinates from Spectral Power Distribution (SPD)

This online CIE 1931 xy calculator takes a spectral power distribution (SPD) input in either 1 nm or 2 nm resolution, and calculates the CIE 1931 xy coordinates. Click on "Input SPD" to load your SPD. Several notes on the SPD input:

- For best results, copy and paste irradiance data from a spreadsheet program or plain text editor, with line breaks between each wavelength data point.

- Wavelength range is 380 - 780 nm.

- Irradiance values are in arbitrary units. The calculator will automatically normalize all values.