Why does your age change from planet to planet?
A year is the time a planet takes to go once around the Sun. On Earth, that trip takes 365.25 days. But each planet moves at its own pace: the farther it is from the Sun, the bigger its orbit… and the longer its year.
Your age on a planet is simply the number of times that planet has gone around the Sun since you were born. The formula: days you have lived ÷ length of the planet’s year (in Earth days).
How long is a year on each planet?
| Planet | Earth days | Earth years |
|---|---|---|
| Mercury | 88 | 0.24 |
| Venus | 225 | 0.62 |
| Earth | 365 | 1 |
| Mars | 687 | 1.88 |
| Jupiter | 4,333 | 11.86 |
| Saturn | 10,759 | 29.46 |
| Uranus | 30,689 | 84.02 |
| Neptune | 60,182 | 164.77 |
| Pluto (dwarf planet) | 90,560 | 247.94 |
What about your birthday on Mars?
On Mars, a year lasts 687 Earth days. Your Martian birthday therefore comes around every 687 days, on a date that shifts every year on our calendar. The calculator shows the exact date of the next one, and a button lets you add it to your calendar so you never miss it. Red cake recommended.
Where were the planets on the day you were born?
When you start the calculation, the pixel-art solar system rewinds to your birth date, then fast-forwards through the years to today. Planets are placed at their real average positions around the Sun (distances are not to scale, though: otherwise Neptune would be off the screen).
Frequently asked questions
How old would I be on Mars?
A Martian year lasts 687 Earth days, about 1.88 Earth years. To find your age on Mars, divide your Earth age by 1.88: at 30, you would be about 16 on Mars. The calculator above does it to the day.
How long is a year on Mars?
Mars takes 687 Earth days to orbit the Sun, roughly 1 year and 10.5 months. Since a Martian day (a “sol”) lasts 24 h 39 min, a Martian year has about 669 sols.
How long is a day on Mars?
A day on Mars, called a “sol”, lasts 24 hours, 39 minutes and 35 seconds. That’s barely longer than a day on Earth, which would be rather handy for settlers.
When is my birthday on Mars?
Your Martian birthday comes around every 687 days from your birth date. The calculator gives you the exact date of the next one and lets you add it to your calendar.
Why am I older on Mercury?
Mercury is the closest planet to the Sun: it goes around it in just 88 days. You would celebrate a birthday roughly every three months, and your age would be more than four times higher than on Earth.
Why is Pluto on the list?
Pluto hasn’t been considered a planet since 2006: it is a dwarf planet. We kept it as a bonus, because a year there lasts 248 years and nobody has ever celebrated a first birthday on it.
Is my birth date stored?
No. The calculation happens entirely in your browser. Your date is only kept on your device for your next visit, and is never sent to our server.
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