Redshift to Velocity Converter

Convert astronomical redshift values to recession velocities using Hubble's Law

Input Parameters

Calculation Results

Calculation Formula

v = z × H₀

Where:
v = Recession velocity (km/s)
z = Redshift
H₀ = Hubble Constant (km/s/Mpc)

Redshift to Velocity Converter Calculator Usage Guide

Learn how to use the Redshift to Velocity Converter calculator and its working principles

What is Redshift?

Redshift (z) is a phenomenon where light or other electromagnetic radiation from an object is increased in wavelength, or shifted towards the red end of the spectrum. In astronomy, redshift is often used to determine the velocity at which distant galaxies are moving away from us due to the expansion of the universe.

How to Use the Calculator

  1. Enter the redshift value (z) of the astronomical object. This is typically a small decimal number (e.g., 0.034 for a galaxy moving away at 3.4% of the speed of light).
  2. Enter the Hubble Constant (H₀). The Hubble Constant is currently estimated to be around 70 km/s/Mpc, but you can adjust this value if you have a different reference.
  3. Click the "Calculate" button to compute the recession velocity.
  4. The result will be displayed in km/s (kilometers per second).

Working Principle

The calculator uses Hubble's Law, which states that the velocity (v) of a galaxy is directly proportional to its distance (d) from us, and the proportionality constant is the Hubble Constant (H₀). For small redshifts, the recession velocity can be approximated as:

v = z × H₀

Where:

  • v is the recession velocity (km/s)
  • z is the redshift
  • H₀ is the Hubble Constant (km/s/Mpc)