Free Cosmic Age Calculator

Estimate the age of the universe as t ≈ 1 / H0 (the Hubble time), providing a rough upper bound for a matter-only universe.

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km/s/Mpc

Hubble Time

440,857,142,857,142,850.00 s

Hubble Time (Gyr)13.9689 Gyr

Hubble Time vs Hubble Constant (H0)

View formula & how it works →

Estimating the Age of the Universe

The simplest age estimate comes from inverting the Hubble constant.

Formula

t_H = 1 / H0

Converting H0 from km/s/Mpc to 1/s requires dividing by 3.086 x 10¹⁹ km/Mpc. The result, about 14 Gyr for H0 = 70, is close to the accepted age of 13.8 Gyr because dark-energy acceleration partially compensates for the deceleration of matter.

Example Calculation

H0 = 70 km/s/Mpc.

  1. 01t_H = 1 / H0 in SI
  2. 02H0 in 1/s = 70 / 3.086e19 = 2.269e-18 s⁻¹
  3. 03t_H = 1 / 2.269e-18 = 4.407e17 s
  4. 04t_H = 4.407e17 / 3.156e16 = 13.96 Gyr

Frequently Asked Questions

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