Age on Other Planets
Example: 30 Earth = 16 Mars years
How old would you be on Mars? Each planet takes a different amount of time to orbit the Sun, so a "year" varies across the solar system. Mercury completes an orbit in 88 Earth days, while Neptune takes 165 Earth years. Enter your age to see how old you would be in planetary years throughout the solar system.
Your age on each planet
Your Planetary Age
Planetary Birthdays
Orbital Period
Progress to Next Birthday
How We Calculate This
Planetary age = (Earth age in days) ÷ (orbital period in Earth days). Orbital periods from NASA Space Place. Earth year = 365.2425 days (Gregorian calendar average).
Methodology last reviewed: October 2023. How SparkCalc works
Sources: NASA Space Place: How Long is a Year on Other Planets? · NASA Science: Orbits and Kepler's Laws · NASA Science: Our Solar System: Planets
Frequently Asked Questions
How is planetary age calculated?
Your age in planetary years = (Earth age × 365.25) ÷ planet's orbital period in days. Each planet takes a different time to orbit the Sun, defining its "year."
Why is Mercury age so high?
Mercury orbits the Sun in just 88 Earth days, so you'd have many more "birthdays" there. In one Earth year, Mercury completes over 4 orbits.
How old would I be on Neptune?
Neptune takes about 165 Earth years to orbit the Sun once. Most humans will never complete a single Neptunian year! Only people born before 1859 would have had a Neptune birthday by now.
What about Pluto?
Pluto's orbital period is about 248 Earth years. No human has ever been alive for a complete Pluto year. Pluto has only completed about 1/3 of an orbit since its discovery in 1930.
Related Calculators
You might also find these calculators helpful: Weight on Other Worlds, and Space Travel Time.
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