🌌Hubble's Law Calculator
Apply v = H₀ × d to find a galaxy's recession velocity or distance, with an adjustable Hubble constant reflecting real measurement uncertainty.
The Hubble constant is still debated — measurements range roughly 67–73 km/s/Mpc, a discrepancy known as the "Hubble tension." Adjust the slider to see its effect.
Free Hubble's Law Calculator
Want to see the expanding universe in action? Our free Hubble's Law Calculator applies v = H₀ × d to find how fast a galaxy is receding from us based on its distance, or work backward from a measured velocity to find distance. Adjust the Hubble constant across its real measured range (67–73 km/s/Mpc) to see how the ongoing "Hubble tension" debate affects the numbers.
Enter a distance in megaparsecs, million light-years, or light-years, and get recession velocity in km/s — plus a comparison to the speed of light for very distant objects. A few real preset galaxies help ground the numbers, along with a note on why Andromeda is a special exception that's actually moving toward us.
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