A “year” is one orbit of the Sun, so faster inner planets give you more birthdays.
How to use the Age on Other Planets Calculator
- Date of birth
- Planet
Results update as you type, and every field accepts the units shown in its menu.
How it works
Your age is converted to days and divided by each planet’s orbital period.
Inputs explained
| Field | What to enter |
|---|---|
| Date of birth | A date |
| Planet | Choose one: Mercury (87.97 days), Venus (224.70), Mars (686.98), Jupiter (4,332.6) … |
What each result means
- Age in Earth days = today() – [Date of birth]
- Age on the planet = [Age in Earth days]÷[Planet]
- Age on Earth = [Age in Earth days]÷365.25
Formula
Planet age = Earth age (days) ÷ planet’s year length (days)Worked example
Inputs — Date of birth: 2000-01-01; Planet: Mars (686.98).
Results — Age in Earth days = 9,794; Age on the planet = 14.26 planet years; Age on Earth = 26.81 years.
Frequently asked questions
Why am I younger on Mars?
A Martian year is almost twice as long as an Earth year.
Has anyone had a birthday on Neptune?
Neptune completed its first orbit since its discovery in 2011.
What formula does the Age on Other Planets Calculator use?
Planet age = Earth age (days) ÷ planet’s year length (days).