Weight Calculator

About the Weight Calculator

Weight is the gravitational force acting on a mass. It equals mass times the local gravitational acceleration g (about 9.81 m/s² on Earth).

Enter the mass in kilograms and the gravity in m/s² (default 9.81 for Earth; use 1.62 for the Moon or 3.71 for Mars). The weight is returned in newtons (N).

How to use this calculator

1. Enter the mass of the object in kilograms, \(m\).
2. Enter the gravitational acceleration in meters per second squared, \(g\).
3. Click calculate to get the weight in newtons, \(W\).
4. Check the steps to see how \(W = m \cdot g\) is applied.

The formula explained

The formula \(W = m \cdot g\) computes weight, which is the gravitational force on an object. Mass is multiplied by gravitational acceleration to get the result in newtons.

• W = weight, measured in newtons \(N\)
• m = mass, measured in kilograms \(kg\)
• g = gravitational acceleration, measured in meters per second squared \(m/s^2\)

Step by step method

1. Write down the mass \(m\) and gravitational acceleration \(g\).
2. Multiply them using \(W = m \cdot g\).
3. Make sure the units work out to newtons \(N\).

Worked example

Problem. Find the weight of a \(12\) kg object on Earth, where \(g = 9.8 \; m/s^2\).

1. Substitute the values into the formula, \(W = 12 \cdot 9.8\).
2. Multiply, \(12 \cdot 9.8 = 117.6\).
3. The weight is \(117.6\) newtons.

Tips and common mistakes

• Use kilograms for mass and \(m/s^2\) for gravitational acceleration, otherwise the result will not be in newtons.
• Do not confuse mass with weight, mass stays the same, but weight changes if \(g\) changes.

Frequently asked questions