How this calculator works
Your age in Earth years is simply the elapsed time divided by the length of an Earth year. On another planet the same elapsed time is divided by that planet's orbital period. Mercury races around the Sun in about 88 Earth days, so a Mercury year is short and your Mercury age is much larger than your Earth age. Neptune takes almost 165 Earth years for one orbit, so a Neptune year is longer than most human lives. The Moon is included as a bonus: its 27.3 day orbit makes a lunar "year" shorter than an Earth month, which is why the lunar age is so large.
Formula
Earth days = elapsed time / 86,400. Age in local years = Earth days / orbital period in Earth days. The periods used are sidereal, meaning one full orbit relative to the distant stars, not the time between two identical seasons.
Worked example
At 30 Earth years old you have lived about 10,957.5 Earth days. Divided by Mercury's 87.969 day orbit, that is about 124.6 Mercury years. On Venus it is about 48.8 Venus years, on Mars about 16.0 Mars years, and on Jupiter only about 2.5 Jupiter years. On the Moon it is about 401 lunar years, because the Moon completes an orbit every 27.3 days.
Advertisement
Frequently asked questions
Why is a year on Mercury shorter than a day on Mercury?
Mercury rotates on its axis very slowly while orbiting the Sun quickly. One solar day on Mercury lasts about two Mercury years. This page uses the orbital period, so it reports Mercury years, not Mercury days.
Are the years sidereal or tropical?
They are sidereal periods, measured against the fixed stars. A tropical year, used for seasons on Earth, is a few minutes shorter. For the other planets the difference is tiny compared with the orbit itself.
Is Pluto included even though it is a dwarf planet?
Yes, because the question is about how long each world takes to orbit the Sun, and Pluto still does that in about 248 Earth years. The label says dwarf planet so the status is clear.
Does the Moon count as a planet?
No. It is included because it is a familiar world with a well-known orbital period around Earth. A lunar year here means one orbit of the Moon around Earth, not a trip around the Sun.