Welcome to K-corrections calculator, simple service allowing one to determine K-corrections of a galaxy, given its redshift and one or more colours. Please fill the form below with a following steps: (1) choose a filter for which you want to calculate K-correction; (2) enter galaxy redshift; (3) then select input colour (if there is a choice); (4) enter colour value; (5) press "Calculate" or hit Enter (be sure that you have JavaScript enabled in your browser). System will produce a K-correction for the filter you specified and 2 formulae for manual calculation of the requested K-correction for given redshift and colour correspondingly, printed in the bottom panel. Please note that galaxy redshift should stay in the range between 0.0 and 0.5.

You can learn about algorithms used for calculation or how to acknowledge this service in the About section. If you need bulk K-corrections calculation, please consider using the code for popular data languages published in Get the code section.

This is an new version of the service including GALEX UV bands. It was originally constructed for and used in the Universal UV-optical Colour-Colour-Magnitude Relation of Galaxies paper. This is an updated version with the redshift coverage up to z=0.5. For consistency reasons we keep as well the historical version developed in 2010.