Weight Calculator

Use it when your task matches one of these common needs: Calculate force in newtons from mass and gravity. Compare Earth and Moon gravity examples. It works best when you already know the measurements, amounts, units, or options the page asks for.

In plain language: The calculator uses weight force = mass x gravity. It multiplies kilograms by m/s2 to get newtons, then converts newtons to pounds-force for comparison. Standard Earth gravity is about 9.80665 m/s2. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.

Mass kg: the amount of matter in kilograms. Mass does not change just because gravity changes. Gravity m/s2: the gravitational acceleration at the location you want to model. Earth standard gravity is about 9.80665 m/s2, the Moon is about 1.62 m/s2, and Mars is about 3.71 m/s2. Newtons: the SI force unit used for the main weight-force answer after mass is multiplied by gravity. Pounds-force: a force-unit conversion from newtons. It is not the same idea as pounds of mass on a scale.

Read the headline answer, then check the supporting lines and examples to understand how the calculator got there. If one input changes, rerun the tool and compare the new answer instead of guessing.

In everyday speech weight and mass are often mixed. This physics tool is not a BMI, ideal weight, height-weight, age-weight, or safety-rated load calculator. Also check the unit, scale, mode, and result limit because small input changes can change the answer.

Mass is the amount of matter. Weight is the force gravity pulls on that mass. The same 70 kg mass has less weight force on the Moon because lunar gravity is smaller.

No. This Weight Calculator is for physics force: mass times gravity. If you want body-weight screening, use the BMI Calculator, Healthy Weight Calculator, or Ideal Weight Calculator instead.

Use 9.80665 m/s2 for standard Earth gravity. Use a different value only when you intentionally want another location, such as about 1.62 m/s2 for the Moon or about 3.71 m/s2 for Mars.

Pounds-force is a force conversion from newtons. Pounds mass is a mass conversion from kilograms. They can look similar under standard Earth gravity, but they answer different questions.

No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.