Planetary birthdays
Mercury races round the Sun in 88 days; Neptune takes nearly 165 years. Enter your birth date to see how many times each planet has circled the Sun in your lifetime, and when your next planetary birthday falls.
Earth days lived
9,799
26.83 Earth years
Age on Mars
14.26
9,537 sols lived
Then 27th on Earth, 1 Jan 2027 · 44th on Venus, 25 Jan 2027 · 113th on Mercury, 20 Mar 2027
| Planet | Age (its years) | Its days lived | Next birthday | When |
|---|---|---|---|---|
| Mercury | 111.39 | 55.7 | 112th 22 Dec 2026 | in 53 days |
| Venus | 43.61 | 83.9 | 44th 25 Jan 2027 | in 87 days |
| Earth | 26.83 | 9,799 | 27th 1 Jan 2027 | in 63 days |
| Mars | 14.26 | 9,537 | 15th 18 Mar 2028 | in 505 days |
| Jupiter | 2.26 | 23,693 | 3rd 2 Aug 2035 | in 3,198 days |
| Saturn | 0.91 | 22,070 | 1st 12 Jun 2029 | in 956 days |
| Uranus | 0.32 | 13,641 | 1st 5 Jan 2084 | in 20,886 days |
| Neptune | 0.16 | 14,598 | 1st 16 Oct 2164 | in 50,390 days |
| Plutodwarf planet | 0.11 | 1,534 | 1st 12 Dec 2247 | in 80,761 days |
Worked out Age on a planet = days lived ÷ its orbit in Earth days. 9,799 days ÷ 686.98 (Mars) = 14.26 Mars years. Earth ages follow your calendar birthday.
A year is one trip around the Sun, so your age on another planet is the number of days you have lived divided by the length of that planet's orbit in Earth days. Someone who has lived 9,799 days is 9,799 ÷ 686.98 = 14.26 Mars years old, but more than a hundred in Mercury years.
The calculator uses each planet's sidereal orbital period, one full circuit measured against the distant stars, from NASA's planetary fact sheets. A planetary birthday is the day that circuit completes, counted from midnight at the start of your birth date. Your Earth age follows the ordinary calendar, so it changes on your real birthday; a 29 February birthday falls on 28 February in other years.
The Its days lived column counts that planet's solar days, sunrise to sunrise: Mars sols last 24.66 hours, while one Venus day lasts 116.75 Earth days. Pluto is included as the best-known dwarf planet. Copy the table, or download it as a spreadsheet-friendly CSV.
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Visit WebTraceCheckA Mars year lasts 686.98 Earth days, almost twice as long as ours, so fewer Mars years fit into your life. Mercury needs only 87.97 days per orbit, so you have had about four Mercury birthdays for every Earth one.
Calculators differ in small ways: some multiply by rounded ratios such as 1.88 for Mars, and NASA's summary table lists tropical years, measured from equinox to equinox. This one divides the exact days you have lived by the sidereal periods, so differences of a few hundredths are normal.
Only at about 164.8 Earth years, so nobody has yet. Neptune has completed just one orbit since it was discovered in 1846. Uranus takes 84 years, so a first Uranus birthday is within reach of a long life.
No. The ages are worked out by this page in your browser and nothing you type is stored or sent.