My Age on Neptune Calculator

Note: When you run this calculator the birth date you enter is saved in a temporary (session) cookie so you do not have re-enter if running the calculator multiple times while visiting our site. The cookie is automatically deleted when your browser closes.

Entry Fields

In the Date of Birth fields, enter your birth date, or of the person for whom you are calculating.

If you prefer to enter Years Old instead of Date of Birth, use this field. If both are provided, Years Old takes priority, and birth date is not used. At this time, Years Old should be a whole number (e.g. 30 Years old, not 30.2 or 30.5).

In the Person's Name , enter the name of person whose Neptunian age you are calculating. If calculating how old you would be on Neptune, you can leave this field empty.

About Age on Neptune Calculator

This calculator translates anyone's current Earth age to their age on the planet Neptune. In addition, if birth date is provided, a birthday chart compares milestone ages (e.g. 1, 16, 21, 30, 50) on Earth and Neptune.

Below you'll find some really interesting info about Neptune, including if one ages faster or slower on Neptune, and how long a day lasts, as compared to here on Earth.

What is Neptune's Position From Sun?

Neptune is the eighth and last planet from the Sun, fourth largest by diameter (third by mass), and also referred to as an ice giant like Uranus, and appears blue due to methane in its atmosphere.

Neptune has one neighboring planet: Uranus, seventh planet from the sun. Pluto had been a neighboring planet (ninth from the Sun), but in 2006 it was demoted to a Dwarf Planet.

The average distance from Uranus to Neptune is 1 billion miles (1.6 billion kilometers).

Note that planet distance's from the Sun and one another vary based on where each planet is in its orbit around the Sun.

What is Temperature on Neptune?

Neptune is extremely cold, with average temperature of -353 Fahrenheit (-214 Celsius).

Despite being 1 billion miles further from the sun than Uranus, Uranus is the coldest planet, with Neptune a close second!

What is Neptune's Circumference and Diameter?

Neptune's diameter is 30,599 miles (49,244 kilometers). The diameter of a planet is the distance from one side across to the other, measured from the planet's center.

Neptune's circumference is 96,129 miles (154,705 kilometers). A planet's circumference is the distance all the way around its equator.

Neptune is about 4 times larger than our Earth.

When was Neptune discovered?

Neptune was discovered in 1846, which was 65 years after Uranus was discovered.

What is absolutely incredible is that Neptune was found by mathematical calculation. This was the 1800s - no computers, just pencil and paper!

Due to irregularities in Uranus' orbit, as early as 1821 Frenchman Alexis Bouvard speculated that it was due to the gravitational forces from another planet. John Couch Adams (English) and Urbain Le Verrier (French), working separately, each calculated where the unknown planet would be.

Le Verrier sent his calculation to Johann Galle in Germany who is said to have located Neptune with his telescope on September 23, 1846, the very night he received the coordinates, finding it within 1 degree of the calculated position.

Needless to say, politics reared its lovely head: France vs. England as to whom was the true calculator. Ultimately, Neptune's discovery was attributed to the three: Galle, Le Verrier, and Adams.

And, when it came time to naming - Yikes! - Neptune was almost called Oceanus or Le Verrier. At one point, things got so heated, that poor Uranus, a billion miles away, almost lost its name: if the new planet was to be named after its rightful discoverer (in France's opinion, Le Verrier), then shouldn't Uranus likewise be re-named Herschel, its discover.

Eventually, Neptune was named like the other planets, after a Roman deity, in this case god of the sea. And, luckily for comedian's everywhere, Uranus got to keep its name!

It is believed that Galileo viewed Neptune in 1612, though he likely was not aware it was a planet.

How long is a year on Neptune?

A year on Neptune is approximately 60,190 days (165 years), which is the length of time it takes for Neptune to do 1 full revolution around the Sun.

For many on Earth, that means that in their lifetime Neptune is about halfway around the Sun.

FYI - Neptune, and all other planets in our Solar System, revolve around the Sun in a counter-clockwise motion.

*An Earth year is often shown as 365.25 days, to account for leap years which have 366 days.

How long is day on Neptune?

A day on Neptune is about 0.67 of an Earth day, making it about 16 hours long.

A day is the amount of time for a planet to make a full rotation on its axis. So while Earth makes a full rotation in 1 day, in that time Neptune has rotated around its axis approximately 1.5 times!

Would I Age Faster on Neptune?

No, you would not age faster on Neptune; You would age slower on Neptune. In fact, if you live to age 90 on Earth, you would only be about 0.55 Neptunian Years!

But, since Neptune rotates 1.5 times faster than earth, you'd have more Neptunian days: for every 2 days on Earth, you would have 3 on Jupiter.

For example, when you are 50 years old on Earth (18,263 days), you'd be about 0.3 Neptunian year, but would have lived 27,257 days on Neptune.

Does Neptune Have Moons? Rings?

Yes, Neptune has 16 known moons, as of the mid-2020s.

First Moon - Triton - Just 17 days after Neptune was discovered in 1846, an amateur English astronomer, William Lassell (1799-1880), who was a brewer by trade, discovered Triton, Neptune's largest moon.

Second Moon (Nereid) - In 1949, over 100 years later, Neptune's second moon Nereid was discovered by Dutch-American astronomer Gerard Kuiper (1905-1973).

Other 14 Neptunian Moons - Then, in 1989, when Voyager 2 flew by, it discovered 6 more moons; thereafter, the rest were found mainly by telescopes on Earth or by Hubble.

Yes, Neptune has at least 5 rings, very dim and dark, comprised of dust and debris, which were not discovered until 1989, when Voyager 2 did its flyby.

Does Neptune Have Seasons?

Yes, Neptune has 4 seasons a year, like on earth. Neptune's axial tilt is 28 degrees, close to that of Earth's which is about 23.5 degrees.

Since a year on Neptune is about 165 years, each Neptunian season lasts about 41 years.

How far is Neptune From the Sun?

Neptune is the furthest planet from the sun, at a mean distance of 2.8 billion miles (4.5 billion kilometers), or 30 astronomical units (AU).

An astronomical unit (AU) is defined as the distance between the Sun and planet Earth, which is 93 million miles (149 million kilometers).

Has Neptune Been Visited?

As of the mid-2020s, Neptune has had just one spacecraft visit it: