Age in Planet Years
Enter a date of birth to see age converted into a year on every planet in the solar system.
About this calculator
This planet age calculator converts age in Earth years into the equivalent number of orbits (years) completed on each planet, based on real orbital periods — from a Mercury year of just 88 Earth days to a Neptune year of about 165 Earth years.
It's a fun way to explore scale in the solar system: someone who is 30 in Earth years has already lived over 124 Mercury years, but hasn't even had a first birthday on Neptune.
How it works
Enter the date of birth
Used to calculate exact age in Earth years.
Calculate
Age in Earth years is divided by each planet's orbital period.
Explore the table
See age on every planet from Mercury to Neptune.
Frequently asked questions
How is a 'year' on another planet defined?
It's the time that planet takes to complete one orbit around the Sun, expressed in Earth years — for example Mars takes about 1.88 Earth years per orbit.
Why is my age so much higher on Mercury?
Mercury orbits the Sun in just 88 Earth days, so many 'years' pass there for every one Earth year.