Skip to main content
Calcimator

Redshift Calculator

Calculate cosmological redshift, recessional velocity, distance, and lookback time using Hubble's law.

Inputs

nm
nm
km/s

Results

Redshift (z)

0

Velocity from Redshift

0 km/s

Distance

142.86 Mpc

Lookback Time

0.14 billion years

Relativistic Redshift0.033932
Distance0.14 Gly

Redshift (z)

0

Velocity from Redshift

0 km/s

Distance

142.86 Mpc

Lookback Time

0.14 billion years

How to Use This Calculator
  1. Start by filling in the input fields below. Results update instantly as you type, so you can experiment with different values to see how they affect the outcome.
  2. Observed Wavelength — Observed wavelength of spectral line Accepts values from 100 nm to 10,000 nm (default: 656.3 nm).
  3. Rest Wavelength — Rest wavelength of spectral line (e.g., H-alpha = 656.3 nm) Accepts values from 100 nm to 10,000 nm (default: 656.3 nm).
  4. Recessional Velocity — Recessional velocity of object Accepts values from 0 km/s to 299,792 km/s (default: 10,000 km/s).
  5. Once all inputs are set, review your results in the Results panel. Here's what each output means:
  6. Redshift (z) — shown as a numeric value. This is the primary result of this calculator.
  7. Velocity from Redshift — shown as a numeric value. This is the primary result of this calculator.
  8. Distance — shown as a numeric value. This is the primary result of this calculator.
  9. Lookback Time — shown as a numeric value. This is the primary result of this calculator.
  10. Relativistic Redshift — shown as a numeric value.
  11. Distance — shown as a numeric value.
  12. Explore the related calculators below if you need deeper analysis or want to approach this topic from a different angle.
Ad Placeholder

Formula

z = (λ_obs - λ_rest) / λ_rest

Related Calculators

Cosmological Distance Calculator

Calculate luminosity distance, comoving distance, angular diameter distance, and lookback time using cosmological models.

Stellar Luminosity Calculator

Calculate stellar luminosity using Stefan-Boltzmann law. Find absolute magnitude, main sequence lifetime, and stellar parameters.

Planetary Transit Calculator

Calculate transit depth, duration, probability, and timing for exoplanet transits.

Ad Placeholder