Age on Other Planets

How old are you on other planets?

A year is simply the time it takes a planet to orbit the Sun once, so your age is different on every world. Mercury races around the Sun in just 88 Earth days, which means a Mercurian "year" is over four times shorter than ours — and your age there is over four times larger. Out at the edge of the Solar System, Neptune takes almost 165 Earth years to complete a single orbit, so most people are less than one Neptune-year old.

Enter your date of birth and this calculator works out your exact age in Earth years to today, then divides that by each planet's orbital period. The result is how many times you would have circled the Sun if you lived on that planet. If you do not want to share a birthday, type your Earth age in years instead.

How it works

Your age in Earth years is converted using each planet's orbital period: Mercury 0.24 years, Venus 0.62, Mars 1.88, Jupiter 11.86, Saturn 29.45, Uranus 84.02 and Neptune 164.79 Earth years. Everything is computed in your browser — nothing is sent anywhere.

FAQ

Why am I so much older on Mercury? Mercury orbits the Sun in only 88 days, so it completes more than four orbits for every Earth year. More orbits means a higher "age" in Mercurian years.

Why am I so young on Jupiter and Neptune? These planets are far from the Sun and take a long time to orbit it — almost 12 years for Jupiter and 165 for Neptune. Fewer orbits in your lifetime means a smaller age.

Does this account for a planet's day length? No. This calculates your age in planet-years (orbits of the Sun), not in local days. A day on Venus, for example, is longer than its year, which is a separate curiosity.

Is the calculation exact? It uses each planet's average orbital period and counts your Earth age in days divided by 365.25, so it is accurate to within a small fraction of a percent — close enough for a fun, educational result.