# How to calculate mass of the sun? Please tell in a simple methamatical way.

##### 1 Answer

#### Answer:

You can calculate the mass of the Sun from Newton's form of Kepler's 3rd law.

#### Explanation:

Newton's form of Kepler's 3rd law describes the orbit of a planet around the Sun. It relates the semi major axis distance of the orbit to the period of the orbit using the equation:

That means:

Where:

p is the orbital period;

G is the gravitation constant;

M is the mass of the Sun;

a is the orbit semi major axis distance.

Rearranging the equation gives:

Now for planet Earth:

and

Putting the values into the equation gives the mass of the Sun: