Redshift to Age Converter
Calculate the Age of the Universe at a Given Redshift
Uses Planck 2018 ΛCDM parameters:
H₀ = 67.74 km/s/Mpc, Ωₘ = 0.309, ΩΛ = 0.691
About the Redshift to Age Converter
The Redshift to Age Converter is a powerful and accurate online tool that instantly converts any cosmological redshift (z) into the corresponding age of the universe at the time the light was emitted. This tool is essential for astronomers, astrophysicists, students, and space enthusiasts who want to understand when in cosmic history a distant galaxy, quasar, or the Cosmic Microwave Background (CMB) emitted its light.
Redshift (z) is one of the most important measurements in modern cosmology. First explained by Edwin Hubble in 1929 and theoretically grounded in general relativity and the Friedmann-Lemaître-Robertson-Walker (FLRW) metric, redshift tells us how much the universe has expanded since the light left its source. A higher redshift means we are looking further back in time.
Scientific Foundation & Accuracy
This Redshift to Age Converter uses the standard ΛCDM (Lambda Cold Dark Matter) cosmological model with parameters from the Planck 2018 final data release:
- Hubble constant H₀ = 67.74 km/s/Mpc
- Matter density Ωₘ = 0.309 (including dark matter and baryonic matter)
- Dark energy density ΩΛ = 0.691
- Radiation density today is negligible for z ≲ 3000
The age is computed by numerically integrating the Friedmann equation:
t(z) = ∫₀^(1/(1+z))₀ dz' / [H₀ (1+z') √(Ωₘ(1+z')³ + ΩΛ + Ωᵣ(1+z')⁴)]
For high precision, we use adaptive Gaussian quadrature with 10⁵-point rules until convergence is better than 10⁻⁶.
Quick Reference Table (Planck 2018)
| Redshift (z) | Lookback Time | Age of Universe | Example Object |
|---|---|---|---|
| 0 | 0 Gyr | 13.79 Gyr (today) | Milky Way |
| 1.0 | 7.73 Gyr | 6.06 Gyr | Typical distant galaxies |
| 2.0 | 10.42 Gyr | 3.37 Gyr | Peak of cosmic star formation |
| 6.0 | 12.85 Gyr | 0.94 Gyr | Earliest galaxies (JWST) |
| 10.0 | 13.35 Gyr | 0.44 Gyr | Reionization era |
| 1100 | 13.79 Gyr | ~380,000 years | CMB – Last Scattering Surface |
When & Why You Should Use This Tool
Use the Redshift to Age Converter whenever you encounter a redshift value from observations and want to know:
- How old was the universe when a distant galaxy formed its stars?
- When did reionization occur?
- How far back are the most distant JWST galaxies?
- What is the age of the universe at the surface of last scattering (CMB)?
User Guidelines
- Enter any positive redshift value (z ≥ 0). Values up to z = 1100 (CMB) are fully supported.
- For very high redshifts (z > 100), radiation density is automatically included.
- The result is given in billions of years (Gyr) with 3 decimal precision.
- Current age of the universe (z = 0) = 13.787 ± 0.020 billion years (Planck 2018).
Importance in Modern Cosmology
Understanding the relationship between redshift and cosmic time is fundamental to interpreting nearly all extragalactic observations. From the formation of the first stars and galaxies at z ≈ 10–20 to the release of the Cosmic Microwave Background at z ≈ 1100, redshift is our primary "time machine". Tools like this Redshift to Age Converter democratize access to precise cosmological calculations that once required specialized software.
This calculator is proudly powered by accurate integration of the Friedmann equation and is regularly updated with the latest consensus cosmological parameters.
Learn more about the physics of redshift on Redshift - Wikipedia or explore agriculture and science topics at Agri Care Hub.
