Frequently Asked Questions
Everything you need to know about the Hubble's Law Calculator.
What is Hubble's law?
A relation stating that a galaxy's recession velocity is proportional to its distance from us: v = H0 × d.
How does this calculator work?
Enter either distance or recession velocity, choose a Hubble constant value, and it solves for the missing quantity.
Is it free?
Completely free, no sign-up, downloads, or limits.
What is the Hubble constant?
A measure of the universe's expansion rate, roughly 67–73 km/s per megaparsec depending on the measurement method — a discrepancy known as the Hubble tension.
Why is Andromeda not included as a typical example?
Andromeda is gravitationally bound to the Milky Way and actually approaching us, so Hubble's law, which describes large-scale cosmic expansion, doesn't apply to it.
Can I use light-years instead of megaparsecs?
Yes, distance can be entered in Mpc, million light-years, or light-years.
What does v/c mean in the results?
It shows the recession velocity as a fraction of the speed of light, useful for very distant, fast-receding galaxies.
What happens with negative distance or velocity?
The calculator rejects negative values with a clear message.
Is my data stored?
No; everything runs in your browser and isn't stored or sent anywhere.
Does it work on mobile?
Yes, fully responsive on all screen sizes.