Your age on other planets
How old would you be if you were born on Mars?
A year is the time a planet takes to orbit the Sun once — and that differs on every planet. Enter your age and see how many "planet years" you would have completed on Mercury, Mars or Neptune. On Mercury you would be surprisingly old; on Neptune perhaps not even one year.
Enter your age on Earth
See how many planet years you have completed.
- 124.6 yrMercurynext birthday in 38.8 Earth days
- 48.8 yrVenusnext birthday in 52.8 Earth days
- 30 yrEarthnext birthday in 365.3 Earth days
- 16 yrMarsnext birthday in 34.2 Earth days
- 2.5 yrJupiternext birthday in 2,040.3 Earth days
- 1 yrSaturnnext birthday in 10,560.9 Earth days
- 0.4 yrUranusnext birthday in 19,727.9 Earth days
- 0.2 yrNeptunenext birthday in 49,231.5 Earth days
- 0.1 yrPlutonext birthday in 79,602.5 Earth days
A planet year = one orbit around the Sun. Orbital periods from NASA Planetary Fact Sheet.
How the conversion works
We divide your age in Earth days by each planet’s orbital period. Mercury orbits the Sun in just 88 days — so you would have almost four times as many birthdays. Neptune takes 165 Earth years for one lap.
Why does a year differ everywhere?
The farther a planet is from the Sun, the longer its path around it — and the slower it moves. Both together make the years of the outer planets extremely long.
Frequently asked questions
On which planet would I have the most birthdays?
On Mercury. Its year lasts just 88 Earth days, so you collect birthdays about four times faster than on Earth.
How old is a 30-year-old on Mars?
About 16 Mars years — a Mars year lasts 687 Earth days, almost twice an Earth year.
Could I ever turn one on Neptune?
Only if you lived past 164 Earth years. Neptune completed its first orbit since its 1846 discovery only in 2011.
Is this about a day or a year?
We use orbital years (one trip around the Sun), not days (one spin on the axis) — two completely different things.
Are leap years included?
Yes, we use the mean Earth year of 365.25 days, which accounts for leap years.
Why is my "planet day" not shown?
This tool counts years (orbits). Day lengths are listed for every planet in our Solar System database.
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