A “year” is just the time a planet takes to orbit the Sun once, and every planet orbits at a different speed. The Age on Other Planets calculator takes your Earth age and converts it into the years of Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune. It is a fun, accurate way to explore the solar system — you are far older on fast little Mercury and may not have completed a single year on distant Neptune.
How it works
The tool first computes your exact age in Earth years by measuring the days between your birth date and today and dividing by 365.25. It then divides that Earth age by each planet’s orbital period (its year length, expressed in Earth years) to get your age on that planet:
planet age = Earth age ÷ orbital period
Planets with a year shorter than Earth’s give a larger age; planets with a longer year give a smaller one.
Example
If you are exactly 30 Earth years old:
- Mercury (0.241 Earth-yr orbit): 30 ÷ 0.241 ≈ 124.6 years
- Mars (1.881 Earth-yr orbit): 30 ÷ 1.881 ≈ 15.9 years
- Neptune (164.79 Earth-yr orbit): 30 ÷ 164.79 ≈ 0.18 years
| Planet | Orbital period (Earth years) | Age at 30 Earth-yr |
|---|---|---|
| Mercury | 0.241 | 124.6 |
| Venus | 0.615 | 48.8 |
| Mars | 1.881 | 15.9 |
| Jupiter | 11.862 | 2.53 |
| Saturn | 29.447 | 1.02 |
| Uranus | 84.017 | 0.36 |
| Neptune | 164.791 | 0.18 |
What the numbers reveal about each planet
Mercury is the fastest — its tiny orbit keeps it close to the Sun and it completes a full circuit in just 88 Earth days. That extreme proximity also means a day on Mercury (sunrise to sunrise) lasts about 176 Earth days, longer than its own year.
Venus has the most unusual rotation in the solar system: it spins so slowly, and in the opposite direction to most planets, that a Venusian day is actually longer than a Venusian year.
Mars is close enough to Earth (1.88 years per orbit) that Martian ages are the most familiar and the most commonly asked about — Mars is the destination most discussed in human spaceflight planning.
Jupiter and Saturn are the two largest planets. Saturn’s distinctive rings make it one of the most visually striking objects in the solar system; at 29 years per orbit, a person born in 1990 is only approaching their first Saturnian birthday.
Uranus and Neptune are cold, distant ice giants. Most people alive today have not yet completed even half a Neptunian year since the planet was discovered in 1846.
All the maths happens in your browser, so your birth date stays on your device.