Earth Mass (M⊕)

AstronomicalCurrent unitApproximate value

About 5.9722×10²⁴ kg, the mass of the Earth. Used to compare planets.

1 Earth mass = 5.9722×10²⁴ kilograms (approximately).

Approximate value. Standards for the Earth mass varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About the Earth mass

Earth mass is the mass of our planet taken as a yardstick for others, and the best current estimate is about 5.9722 x 10^24 kg, with an uncertainty near one part in ten thousand. NASA's Earth fact sheet and the International Astronomical Union's recommended value agree with this figure.

No scale can weigh a planet, so the mass is found by dividing the planet's gravitational parameter by Newton's constant G. The parameter itself is known to about two parts in a billion from satellite tracking, but G is known only to roughly two parts in a hundred thousand, so the mass inherits that limit. For this reason astronomers often quote GM or mass ratios instead.

The history begins with Nevil Maskelyne's Schiehallion experiment in Scotland in the 1770s, whose result implied a density about one fifth too low. Henry Cavendish's laboratory torsion balance of 1798 produced a density within about 1 percent of the modern one. Uncertainty fell to about 0.2 percent by the 1890s. About 333,000 Earth masses make one solar mass.

Sources: Wikipedia: Earth mass; NASA Earth Fact Sheet

Earth Mass conversion chart

1 Earth mass expressed in every other weight & mass unit:

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