calciz

Hubble's Law Calculator

How fast the expansion carries a galaxy away, or how far it is.

Mpc
1 megaparsec is 3.26 million light-years.
km/s

The expanding universe in one line

v = H₀ × d

Galaxies recede at a speed proportional to their distance: at 100 Mpc, about 7,000 km/s. This calculator uses H₀ = 70 km/s/Mpc, a round middle of the measured range; different methods currently disagree between about 67 and 73, a genuine open problem called the Hubble tension.