Processing...

`m = M(r/R)`

Enter a value for all fields

The ** Mass of an Extra-solar Planet** calculator computes the mass of a planet based on the mass of the star (**M**), the distance to the star (**R**) and the distance to the planet (**r**).

**INSTRUCTIONS:** Choose the preferred units and enter the following:

- (
**M**) This is the mass of the star. - (
**R**) This is the orbital radius of the planet. - (
**r**) This is the orbital radius of the star about the center of mass.

**Planet Mass (m):** The calculator returns the mass of the planet in Jupiter_Mass units (multiples of the mass of Jupiter). However, this can be automatically converted to other mass units (e.g. Earth_Mass or kilograms) via the pull-down menu.

If you know the mass of a star, and the orbital radius of the star and the planet, you can compute the mass of the planet using the fact that the center of mass obeys the relation: m•R = M•r. The formula for the mass of a planet is:

m = (M•r)/ R

where:

- m = mass of the planet
- M = mass of the star
- r = orbital radius radius of the star
- R = orbital radius of the planet

Consider Jupiter in our own solar system:

- (M) The mass of our star (the Sun) is 1.0 Solar_Mass
- (R) This orbital radius of Jupiter is 5.2 ua
- (r) The orbital radius of our Sun around the solar system's center of mass is 0.005 ua

If you enter the above, the calculator returns an exoplanet mass of approximately 1 Jupiter Mass which fits the model and describes our solar system.

- Kepler's 3
^{rd}Law formula T² = (4π • R³)/(G • M) - Small Angle Formula
- Flux and Magnitude formulas
- Telescope formulas
- Mass formulas
- Relative Size Formulas
- Wavelength Formulas
- Luminosity and other Formulas

**Related Astro Calculators:**

- Kepler's 3
^{rd}Law Calc has Kepler's 3^{rd}law solved for each parameter. - Astronomy Calculator contains basic formulas for a college level Introduction to Astronomy
- Exoplanet Calculator contains formulas for studying planets outside of our Solar System.
- Astronomical Distance Calculator provides the distance from the Earth to numerous astronomical bodies (e.g. Sun, Moon, planets, stars, Milky Way's Center and Edge, Andromeda Galaxy)
- Astronomical Distance Travel Time Calculator computes the time to travel to distant parts of space at different velocities.
- Ellipse Calculator
- 3D Vector Calculator:
- Drake Equation Calculator
- Seager Equation Calculator
- Friedman Equation Calculator
- Exoplanet Calculator contains formulas for studying planets outside of our Solar System.
- Astronomical Distance Calculator provides the distance from the Earth to numerous astronomical bodies (e.g. Sun, Moon, planets, stars, Milky Way's Center and Edge, Andromeda Galaxy)
- Astronomical Distance Travel Time Calculator computes the time to travel to distant parts of space at different velocities.
- Radius of Perigee
- Radius of Apogee