Age on Other Planets

A “year” is just the time a planet takes to orbit the Sun once, and every planet orbits at a different speed. The Age on Other Planets calculator takes your Earth age and converts it into the years of Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune. It is a fun, accurate way to explore the solar system — you are far older on fast little Mercury and may not have completed a single year on distant Neptune.

How it works

The tool first computes your exact age in Earth years by measuring the days between your birth date and today and dividing by 365.25. It then divides that Earth age by each planet’s orbital period (its year length, expressed in Earth years) to get your age on that planet:

planet age = Earth age ÷ orbital period

Planets with a year shorter than Earth’s give a larger age; planets with a longer year give a smaller one.

Example

If you are exactly 30 Earth years old:

• Mercury (0.241 Earth-yr orbit): 30 ÷ 0.241 ≈ 124.6 years
• Mars (1.881 Earth-yr orbit): 30 ÷ 1.881 ≈ 15.9 years
• Neptune (164.79 Earth-yr orbit): 30 ÷ 164.79 ≈ 0.18 years

All the maths happens in your browser, so your birth date stays on your device.