How old are you on other planets?
Every world takes its own time to go around the Sun. Enter a birthday to see your age on each one, and the day your next birthday there comes.
This is an example. Change the date to your own birthday.
Laps around the Sun
Each ring is a world, Mercury in the middle. The arc shows how far that world has gone around the Sun since your last birthday there; the number is how many full laps you’ve lived.
Coming up in your family
The Sun, dwarf planets, asteroids and a comet
| World | Age | Next birthday |
|---|
Some asteroid dates use average orbits because their day-by-day data didn’t load.
Put every one of these on the wall
Our calendars find every birthday your family has across the solar system in the year ahead: first Jupiter birthdays, a grandparent’s second Saturn birthday, a Mars birthday every 23 months, laps of real asteroids, and a Sun-day every 25 days. Each month’s art is chosen for the birthdays in it.
Ten styles, from 1881 astronomical drawings to synthwave neon. Printed and shipped to your door, or as a PDF to print at home.
See the calendars
How it works
- A birthday is one full trip around the Sun, counted from the day you were born. Mercury makes the trip in 88 days, Neptune in 165 years.
- Planet years come from NASA’s planetary fact sheets.
- Asteroids and the comet follow each world’s real path, day by day, from NASA JPL’s Horizons system (1901–2099). That’s why Apophis’s dates change after its close pass by Earth in April 2029.
- The Sun doesn’t orbit anything nearby, but it spins. Its equator turns once every 25.05 days, and each turn is a Sun-day.
- Earth birthdays are the usual calendar date. February 29 birthdays fall on February 28 in other years. Time of birth is ignored, which can move a date by a day.
Questions
Is anything I type saved or sent anywhere?
No. Every number is calculated in your browser. The names and dates stay on your device so the page remembers them next time; nothing reaches us.
Why is my age on Mercury so high?
Mercury is the closest planet to the Sun and the fastest, so its year is only 88 Earth days. You have a Mercury birthday about four times a year.
Why do the outer rings barely move?
The giant planets are far from the Sun and slow. A Jupiter year is almost 12 Earth years and a Neptune year is 165, so most people never have a first Neptune birthday.
Can I add pets?
Yes. Add them as another person; pets have birthdays on other worlds too.