How old would you be on Mercury, Venus, Mars and beyond? Divide your Earth age by each planet's year length.
A planet's year is its orbital period. On Mercury (0.241 Earth years) you age fast; on Neptune (164.8 years) you would still be a baby.
Your planetary ages
How to use this tool
Or enter your birth date for an exact age.
All seven planets are shown at once.
The planet with the shortest period gives you the next celebration soonest — Mercury.
Copy the table to compare ages with friends.
Formula & worked example
At 30 Earth years old you would be about 15.9 Mars years, 124.5 Mercury years, but only 0.18 Neptune years old — not even one Neptune birthday yet.
Limitations — read this before you rely on it
Uses mean orbital periods and 365.25 days per Earth year. It counts birthdays by orbital periods only — it does not model planet days, seasons or relativistic effects.
Frequently asked questions
Mercury's year is only 88 days (0.241 Earth years), so you rack up Mercury birthdays about four times faster.
Neptune takes 164.8 Earth years to orbit the Sun once, so a 30-year-old has lived less than a fifth of a Neptune year.
Yes if you enter a birth date: Earth age is computed from it (using 365.25 days per year), then divided by each orbital period.
Pluto's year is 248 Earth years; it is omitted as a dwarf planet, but the same division applies: 30 ÷ 248 ≈ 0.12 Pluto years.
No — a year is one orbit around the Sun; a day is one spin. Venus famously spins slower than it orbits.