Date & time · Fun
Your age on other planets.
A year on another planet is the time it takes to orbit the Sun. Enter your birth date to see your age in planet years.
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How to calculate your age on other planets
Count the days you have been alive and divide by the planet's orbital period, the length of its year in Earth days. NASA's Planetary Fact Sheet gives these periods:
| Planet | Orbital period |
|---|---|
| Mercury | 88 Earth days |
| Venus | 224.7 Earth days |
| Earth | 365.2 Earth days |
| Mars | 687 Earth days |
| Jupiter | 4,331 Earth days |
| Saturn | 10,747 Earth days |
| Uranus | 30,589 Earth days |
| Neptune | 59,800 Earth days |
| Pluto | 90,560 Earth days |
Worked example. Born 15 March 1990, on 8 October 2026 you have lived 13,356 days. That is 19.44 Mars years (13,356 / 687.0), 3.08 Jupiter years (/ 4,331) and 151.77 Mercury years (/ 88.0). Your next Mars birthday is 2027-10-27.
The Earth row divides by NASA's 365.2 days, so it can differ slightly from your calendar age. Pluto is classed as a dwarf planet and is included for fun. A "birthday" here means completing a whole planet year since birth.
Frequently asked questions
How old am I on Mars?
Divide your age in days by 687. A 36-year-old Earth person has lived about 13,000 days, which is about 19 Mars years. The tool does the exact sum.
How do I calculate my age on another planet?
Days lived divided by the planet's orbital period in Earth days.
Where do the orbital periods come from?
NASA's NSSDC Planetary Fact Sheet. Mercury is 88.0 days, Venus 224.7, Mars 687.0, Jupiter 4,331, Saturn 10,747, Uranus 30,589, Neptune 59,800 and Pluto 90,560.
Will I have a birthday on Neptune?
Only if you live to complete a Neptune year, which is about 164 Earth years. The tool shows the date of your next one regardless.
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Scope
For information and fun only. Not legal, medical or genealogical advice; rules about ages, eligibility and family relationships vary by place and program.