Your Age on
Other Planets
How old would you be if you were born on another planet?
How is your age on other planets calculated?
A planet's year is the time it takes to complete one full orbit around the Sun — called its orbital period. Mercury takes just 88 Earth days, while Neptune takes 165 Earth years, so your age in planetary years varies enormously depending on which planet you are on.
The calculation divides your age in Earth years by each planet's orbital period in Earth years. For example, if you are 30 Earth years old, you would be about 124 years old on Mercury but not yet 1 year old on Neptune. Enter your date of birth above and Clockr applies this formula to every planet in the solar system instantly.
This is a thought experiment rather than a literal measure of age. Planets have very different conditions — gravity, atmospheres, and temperatures — that would make human life impossible on most of them. Your cosmic age is purely mathematical, a fun way to explore how time works differently across the solar system.
Frequently asked questions
How long is a year on Mars?
A Martian year lasts 687 Earth days — roughly 1.88 Earth years. Mars takes nearly twice as long as Earth to orbit the Sun, so you age about half as fast in Martian years. If you are 36 Earth years old, you would be about 19 on Mars.
How long is a year on Jupiter?
A year on Jupiter lasts about 11.86 Earth years — roughly 4,333 Earth days. Jupiter's massive orbit means you would celebrate far fewer birthdays there. A 30-year-old on Earth would be just 2.5 years old on Jupiter.
Which planet has the shortest year?
Mercury has the shortest year in the solar system, completing one orbit in just 88 Earth days — about 0.24 Earth years. Because it is closest to the Sun, Mercury travels the fastest and finishes its orbit in less than three Earth months.
Which planet has the longest year?
Neptune has the longest year, taking about 164.8 Earth years to orbit the Sun once. At nearly 4.5 billion kilometres from the Sun, Neptune moves slowly — most people alive today would not yet have reached their first Neptune birthday.
How old would I be on Mars if I was born in 1990?
If you were born in 1990, you are roughly 36 Earth years old in 2026. On Mars, that works out to about 19 Martian years (36 ÷ 1.881). Enter your exact date of birth above for a precise result that accounts for months and days, not just the birth year.
Could humans ever live on another planet?
Mars is the most realistic candidate — NASA and SpaceX both target human missions there within decades. Venus and the gas giants are far too hostile for surface life. Even Mars would require sealed habitats, radiation shielding, and life-support systems. Living on another planet remains science fiction for now, but the maths of planetary age is already here.
How long is a day on each planet?
A day (one full rotation) differs from a year on every planet. Earth's day is 24 hours. Mars takes 24 hours 37 minutes. Jupiter spins fastest at just under 10 hours. Venus rotates so slowly that its day (243 Earth days) is longer than its year (225 Earth days). This calculator measures age in orbital years, not rotation days.
What is an orbital period?
An orbital period is the time a planet takes to complete one full revolution around the Sun. It defines the length of that planet's year. Earth's orbital period is 365.25 days. The farther a planet is from the Sun, the longer its orbital period — which is why outer planets have much longer years than inner ones.