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Age on Other Planets
Based on real orbital periods around the Sun
years
Your Age Across the Solar System
Based on 30 Earth years
Your Age Across the Solar System
On Mercury a year lasts just 88 Earth days, so a 30-year-old is about 124.6 years old on Mercury, 15.95 on Mars and only 0.18 on Neptune. Enter your Earth age above and the calculator divides your age in days by each planet's orbital period from NASA's planetary fact sheets.
Your Age on Each Planet at a Glance
Common Earth ages converted with NASA's sidereal orbital periods. Pluto is a dwarf planet, included for comparison.
| Earth age | Mercury | Venus | Mars | Jupiter | Saturn | Uranus | Neptune | Pluto |
|---|---|---|---|---|---|---|---|---|
| 10 | 41.52 | 16.25 | 5.32 | 0.84 | 0.34 | 0.12 | 0.06 | 0.04 |
| 18 | 74.74 | 29.26 | 9.57 | 1.52 | 0.61 | 0.21 | 0.11 | 0.07 |
| 25 | 103.80 | 40.64 | 13.29 | 2.11 | 0.85 | 0.30 | 0.15 | 0.10 |
| 30 | 124.56 | 48.76 | 15.95 | 2.53 | 1.02 | 0.36 | 0.18 | 0.12 |
| 40 | 166.08 | 65.02 | 21.27 | 3.37 | 1.36 | 0.48 | 0.24 | 0.16 |
| 50 | 207.60 | 81.27 | 26.58 | 4.22 | 1.70 | 0.60 | 0.30 | 0.20 |
| 65 | 269.88 | 105.66 | 34.56 | 5.48 | 2.21 | 0.77 | 0.39 | 0.26 |
| 80 | 332.16 | 130.04 | 42.53 | 6.74 | 2.72 | 0.95 | 0.49 | 0.32 |
How Long a Year Lasts on Each Planet
A planet's year is one full orbit of the Sun. The formula is simple: planet age = (Earth age × 365.25) ÷ orbital period in Earth days. For a 30-year-old on Mars: 30 × 365.25 = 10,957.5 days, and 10,957.5 ÷ 686.98 = 15.95 Mars years.
| Body | Orbital period (Earth days) | In Earth years | Years per Earth year |
|---|---|---|---|
| Mercury | 87.97 | 0.24 | 4.152 |
| Venus | 224.70 | 0.62 | 1.625 |
| Earth | 365.26 | 1.00 | 1.000 |
| Mars | 686.98 | 1.88 | 0.532 |
| Jupiter | 4,332.59 | 11.86 | 0.084 |
| Saturn | 10,755.70 | 29.45 | 0.034 |
| Uranus | 30,685.4 | 84.01 | 0.012 |
| Neptune | 60,189.0 | 164.79 | 0.006 |
| Pluto (dwarf planet) | 90,560 | 247.94 | 0.004 |
These are sidereal periods, measured against the distant stars. Orbits are ellipses, so a planet moves faster near the Sun and slower far from it, but one full lap always takes the same time.
Planetary Birthdays
Mercury: every 88 days
You get a new Mercury birthday roughly four times a year. A 1-year-old has already had four.
Mars: every 687 days
Your Mars birthday comes about every 1 year and 322 days. By 30 you have had 15 of them.
Jupiter and Saturn: once or twice a lifetime
You turn 1 on Jupiter at 11.86 Earth years, 2 at 23.72, 3 at 35.59, 4 at 47.45 and 5 at 59.31. Your first Saturn birthday arrives at about 29 years and 5 months, and the second at about 58 years 11 months.
Uranus, Neptune and Pluto: not in this lifetime
A first Uranus birthday needs 84 Earth years. Nobody has lived a full Neptune year (164.8 Earth years), let alone a Pluto one.
Method and sources. Planet age = (Earth age × 365.25 days) ÷ the planet's sidereal orbital period in Earth days. Orbital periods: NASA Space Science Data Coordinated Archive (NSSDCA) Planetary Fact Sheets. Pluto has been classed as a dwarf planet by the International Astronomical Union since 2006 and is shown for comparison only. For fun: planet ages do not describe biological aging.
Space Age Questions
Each planet has a different orbital period, the time it takes to complete one orbit around the Sun. That is the planet's "year." Your age on another planet equals your total age in Earth days divided by that planet's year in Earth days. For example: 30 Earth years = 30 × 365.25 = 10,957.5 days. Divide by Mars's orbital period (686.98 days) and you get 15.95 Mars years. The calculator uses the sidereal orbital periods from NASA's planetary fact sheets.
Orbital periods in Earth days, from NASA's planetary fact sheets: Mercury 87.97 days (0.24 Earth years). Venus 224.70 days (0.62). Earth 365.26 days. Mars 686.98 days (1.88). Jupiter 4,332.59 days (11.86). Saturn 10,755.70 days (29.45). Uranus 30,685.4 days (84.01). Neptune 60,189.0 days (164.79). The dwarf planet Pluto takes 90,560 days (247.94 Earth years). The closer a planet is to the Sun, the shorter its orbit and the faster it moves, because the Sun's pull is stronger there.
Mercury orbits the Sun in only 88 Earth days, the fastest of all planets. For every Earth year you live, you add about 4.15 Mercury years, so a 30-year-old on Earth is roughly 124.6 in Mercury years. Mercury spins slowly: it rotates only 1.5 times per orbit, and one solar day (sunrise to sunrise) lasts about 176 Earth days, twice as long as its year. With almost no atmosphere to hold heat, its surface swings from about 430°C (800°F) in the day to about −180°C (−290°F) at night.
Neptune takes 164.8 Earth years to complete one orbit, so no human has ever lived through a full Neptune year. Neptune was discovered in 1846 and completed its first full orbit since discovery only in 2011. A 30-year-old on Earth is just 0.18 Neptune years old, and even the oldest person on record (122 years) would be under 0.75 Neptune years old.
This calculator uses orbital periods, not biological aging. Gravity does affect time, though: Einstein's general relativity shows that clocks run slightly slower in stronger gravitational fields (gravitational time dilation). Near a massive planet like Jupiter, time would pass a tiny bit slower than on Earth, far too little to notice in a human lifetime. For astronauts the bigger effect is speed: moving fast makes clocks run slower, so crew on the International Space Station age slightly less than people on the ground, about 0.005 seconds over a 6-month mission.
Mercury is the fastest planet, orbiting the Sun at an average speed of 47.4 km/s (about 106,000 mph) and completing its orbit in just 88 Earth days. Neptune is the slowest, moving at 5.43 km/s (about 12,100 mph) and taking 164.8 Earth years per orbit. Planets closer to the Sun orbit faster because the Sun's gravity is stronger there, and Kepler's second law means each planet also speeds up at the closest point of its elliptical orbit. Earth travels at about 29.78 km/s, roughly 67,000 mph.
Venus, with 224.7 Earth days per orbit, about 62% of an Earth year. Mercury (88 days) comes next, and Mars (687 days, 1.88 Earth years) after that. Venus is often called Earth's twin for its size, but its surface is about 465°C (870°F) with an air pressure 92 times Earth's. It takes 243 Earth days to spin once on its axis, longer than its 225-day year, and it is the only planet where that is true. Venus also rotates backwards compared with most planets, so the Sun rises in the west and sets in the east.
Pluto was reclassified as a "dwarf planet" by the International Astronomical Union in 2006, mainly because it has not cleared the neighborhood around its orbit. Pluto takes 248 Earth years to orbit the Sun, so a 30-year-old would be just 0.12 Pluto years old. It has not completed a single orbit since its discovery in 1930 and will not do so until 2178. Its moon Charon is so large relative to Pluto that the pair is sometimes called a double dwarf planet, tidally locked so the same sides always face each other.
A year is simply the time for one complete orbit around the Sun, whatever the planet is made of, so it is well defined for Jupiter, Saturn, Uranus and Neptune. The "day" is trickier: gas giants do not rotate as a solid body, and different latitudes spin at different speeds. Jupiter's equator turns in about 9 hours 50 minutes, making it the fastest-rotating planet. Its year (4,333 Earth days) divided by its day (about 9.9 hours) gives about 10,476 Jupiter days per Jupiter year, against Earth's 365.
A Mars year is 1.88 Earth years long, and a Mars solar day (called a "sol") is about 24 hours and 40 minutes, very close to an Earth day. That makes Mars the most Earth-like planet for daily rhythms, and NASA already schedules rover operations in sols. Thirty Earth years equal 15.95 Mars years, or roughly 10,660 sols. Mars has seasons because its axis is tilted 25.2° (Earth's is 23.4°), but each season lasts about twice as long as on Earth. It also has the largest dust storms in the solar system, some lasting months.
A Mars year lasts 686.98 Earth days, so a Mars birthday comes around every 1 year and about 322 days. A 30-year-old on Earth is 15.95 in Mars years and has had 15 Mars birthdays. Future Mars settlers would also have longer seasons, each roughly twice as long as on Earth.
At 11.86 Earth years, the time Jupiter takes to orbit the Sun (4,332.59 Earth days). You turn 2 on Jupiter at 23.72, 3 at 35.59 and 5 at 59.31. Saturn is slower: your first Saturn birthday is at about 29.45 Earth years.