Hubble Distance Calculator Formula

Understand the math behind the hubble distance calculator. Each variable explained with a worked example.

Use the Hubble Distance Calculator

Formulas Used

Distance

distance_mpc = velocity / hubble_constant

Distance (Mly)

distance_mly = velocity / hubble_constant * 3.26156

Variables

VariableDescriptionDefault
velocityRecession Velocity(km/s)7000
hubble_constantHubble Constant (H0)(km/s/Mpc)70

How It Works

Hubble's Law

v = H0 × d or equivalently d = v / H0

  • *v* = recession velocity (km/s)
  • *H0* = Hubble constant (≈70 km/s/Mpc)
  • *d* = distance in megaparsecs

    • This linear relation holds well for galaxies not too far away (z < 0.1). For larger distances, cosmological models are needed.

    Worked Example

    A galaxy recedes at 7 000 km/s with H0 = 70 km/s/Mpc.

    velocity = 7000hubble_constant = 70
    1. 01d = v / H0 = 7000 / 70 = 100 Mpc
    2. 02In Mly: 100 × 3.262 = 326.2 million light-years

    Ready to run the numbers?

    Open Hubble Distance Calculator