Enter your Earth age (or a birth date) to see your age on each planet.
Pick a birth date and your Earth age is filled in from today automatically.
About this tool
The Age on Other Planets Calculator turns your Earth age into the number of years you would have lived on each planet. A planetary year is one full orbit of the Sun, and because every planet circles at a different speed, your age looks wildly different from world to world.
The maths is age_on_planet = earth_age × (Earth's orbital period ÷ the planet's orbital period). Measured in Earth years this simplifies to earth_age ÷ planet_period, where Mercury takes 0.24 Earth years to orbit, Venus 0.62, Mars 1.88, Jupiter 11.86, Saturn 29.46, Uranus 84.01 and Neptune 164.8. So a 30-year-old is nearly 125 on Mercury but has not yet finished a single Neptunian year, and would be about 15.96 years old on Mars.
Enter your age directly, or pick your birth date and the tool works out your exact Earth age first from today's date. All calculation happens in your browser — nothing you type leaves your device.
Frequently asked questions
How is my age on another planet calculated?
It divides your Earth age by the planet's orbital period in Earth years. Because a year on that planet is one orbit of the Sun, a faster-orbiting planet like Mercury racks up far more birthdays than Earth.
Why am I so much older on Mercury than on Neptune?
Mercury completes an orbit in just 0.24 Earth years, so it fits many of its short years into your lifetime. Neptune takes 164.8 Earth years per orbit, so most people are less than one Neptunian year old.
Can I enter a birth date instead of my age?
Yes. Pick a birth date and the calculator computes your precise Earth age (in years, including the fraction) from today's date, then converts that to each planet automatically.
Why isn't Pluto or the Moon listed?
This tool covers the eight planets that orbit the Sun. The Moon orbits Earth rather than the Sun, and Pluto is now a dwarf planet, so neither has a comparable planetary year here.
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