Calculate cosmological redshift, recession velocity, and distance.
Wavelengths
Cosmological Data
Enter wavelengths to calculate
About this calculator
Quick Reference
zRedshift parameter
c299,792 km/s
H070 km/s/Mpc
1 Mpc3.26 Million Ly
Overview
Redshift (z) describes how light from distant galaxies is stretched to longer wavelengths due to the expansion of the universe. It is a key metric for determining recession velocity.
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Pro Tips
z = (λ_obs - λ_emit) / λ_emit
Positive z indicates the object is moving away (Redshift).
Negative z indicates the object is moving closer (Blueshift).
For z << 1, velocity v ≈ z * c.
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Fun Facts
"The most distant known galaxy, GN-z11, has a redshift of z = 11.09, meaning we see it as it was 13.4 billion years ago."
"Hubble's Law relates redshift to distance: v = H0 * d."
"Gravitational redshift also occurs when light escapes a massive object like a star or black hole."
