Weight Calculator guide
Weight Calculator: Weight in Newtons on Earth and Other Planets
Use our weight calculator to convert mass into weight in newtons, and see what you would weigh on the Moon, Mars and other planets.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
In science, weight is a force: the pull of gravity on a mass. Our Weight Calculator converts mass into weight and shows how it changes on other worlds.
How to use the calculator (Weight Calculator)
Enter a mass and choose its units. You'll see the weight in newtons, kilonewtons and pounds-force, plus a table for other planets.
The formula
W = m × g
- W is weight in newtons (N)
- m is mass in kilograms
- g is the acceleration due to gravity, 9.81 m/s² on Earth
Gravity on other worlds
| Place | Gravity (m/s²) | 70kg feels like |
|---|---|---|
| Moon | 1.62 | 11.6kg |
| Mars | 3.71 | 26.5kg |
| Earth | 9.81 | 70kg |
| Jupiter | 24.79 | 177kg |
A worked example
With the calculator's default settings, a mass of 70kg has a weight of 70 × 9.81 = 686.5N on Earth. On the Moon it would weigh just 113N.
Frequently asked questions
Why do we say we weigh 70kg?
In everyday language, "weight" means mass. Scales measure the force but display it as the matching mass on Earth.
Would my mass change on the Moon?
No. Your mass stays the same; only your weight changes.
Is gravity the same everywhere on Earth?
Almost. It's slightly stronger at the poles than the equator, by about 0.5%.
Sources and further reading
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.