The equation to calculate weight from mass is:

Weight = mass x gravitational field strength

or

(W=mg)

Please note the units here, they are incredible important when completing the calculations as the Weight must be in Newtons (N), the mass must be in Kilograms (kg) and the gravitational field strength must be in N/kg.

W(N) = m(kg) x g(N/kg)

If the mass is not given in kg then you must convert it to kg.

In the example below, the mass is given in g and must be converted to kg before using it in the W=mg equation:

You can also re-arrange W=mg to find mass and g if a scenario requires this.

Here are the re-arrangements for m and g, and two example calculations: