A star apparent magnitude is how bright it looks from Earth, but that mixes up its true output with how far away it is. Absolute magnitude fixes this by defining brightness as it would appear from a standard distance of ten parsecs, letting you compare stars fairly. The link is the distance modulus: apparent minus absolute magnitude equals five times the base ten logarithm of the distance in parsecs minus five. This calculator solves for whichever quantity you leave blank, so you can find absolute magnitude from a known distance, or distance from the magnitude gap. It also converts the distance to light years. Enter any two values below and it computes the third entirely in your browser.
A star apparent magnitude is how bright it looks from Earth, but that mixes up its true output with how far away it is. Absolute magnitude fixes this by defining brightness as it would appear from a standard distance of ten parsecs, letting you compare stars fairly.
Yes. Absolute Magnitude Calculator is completely free, with no sign-up and no usage limits.
Yes. Absolute Magnitude Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Absolute Magnitude Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.