The 'Space Age' Calculator

Every year, the Earth completes one orbit of the Sun, and every year, you have a birthday! And during a year, the Earth rotates 365 times on its axis and we experience 365 sun rises and sun sets. Use the calculator to find out how old would you be on another planet!


​Use the 'Space Age' calculator to find out:

  • How many birthdays would you have had if you lived on another planet
  • How many days you have experienced on Earth
  • If it is the same number of days on another planet
  • And if you can compare your age in years and days on all 8 planets in the Solar System


So why is it different?

The planets in the Solar System travel around the Sun at different speeds. So they take different amounts of time to complete an orbit of the Sun. This means 1 year on another planet is not the same amount of time as 1 Earth year.

Our Earth completes just over 365 rotations for every obit of the Sun. This gives us 365 days in an Earth year. Other planets spin at different speeds. Some complete hundreds of days during their year, others, just a few.

A birthday cake with lit candles. Above it are the eight planets of our Solar System
How many birthdays would you have had on another planet?
Credit: The Schools' Observatory