Case 1
- Mass
- 70kg
- Gravitational acceleration
- 9.80665m/s²
686.4655N
Open with these valuesWeight Force Calculator
686.4655N
Result: 686.4655 NWeight is a force, not a mass: it comes out in newtons, and it changes with where you stand. A 70 kg body weighs 686.4655 N on Earth at standard gravity, about 113 N on the Moon and about 260 N on Mars. The kilograms never change — only g does.
The numbers at a glance
Held fixed: Mass 70.000 kg.
| Gravitational acceleration (m/s²) | Result (N) |
|---|---|
| 0.00000 | 0.0000 |
| 2.50000 | 175.0000 |
| 5.00000 | 350.0000 |
| 7.50000 | 525.0000 |
| 9.80665Your value | 686.4655 |
| 10.00000 | 700.0000 |
| 12.50000 | 875.0000 |
| 15.00000 | 1,050.0000 |
| 17.50000 | 1,225.0000 |
Worked examples
Case 2
- Mass
- 70kg
- Gravitational acceleration
- 1.62m/s²
113.4000N
Open with these valuesCase 3
- Mass
- 1000kg
- Gravitational acceleration
- 3.71m/s²
3,710.0000N
Open with these valuesHow it's calculated
W = m × g
- StepEnter the mass in kilograms — that is the figure a scale shows.
- StepEnter the local gravity: 9.80665 on Earth, 1.62 on the Moon, 3.71 on Mars.
- ResultRead the weight in newtons, not in kilograms.
Reference table
| Mass, gravity | What it is | Weight |
|---|---|---|
| 0.145, 9.80665 | A baseball on Earth | 1.42196 |
| 10, 1.62 | Ten kilograms on the Moon | 16.2 |
| 10, 3.71 | The same ten kilograms on Mars | 37.1 |
| 70, 9.80665 | An adult on Earth | 686.4655 |
| 1000, 3.71 | One tonne on Mars | 3710 |
Questions
How do I calculate the weight force?
Multiply the mass by the local gravitational acceleration: W = m × g. Kilograms and metres per second squared give newtons — a 70 kg person on Earth has 70 × 9.80665 = 686.4655 N.
What is the difference between weight and mass?
Mass is the amount of matter in an object, measured in kilograms, and it never changes. Weight is the gravitational force on that mass, measured in newtons, and it depends on where you are. A 70 kg person weighs about 686 N on Earth and only about 113 N on the Moon.
What unit is the weight force measured in?
Newtons (N), the SI unit of force, where one newton is one kilogram-metre per second squared. Enter the mass in kilograms and gravity in metres per second squared and the answer is in newtons.
What value of g should I use for Earth?
The standard value 9.80665 m/s², which was fixed by definition in 1901 rather than measured. Real gravity varies slightly with latitude and altitude, a little weaker at the equator and on high ground.
How much would I weigh on the Moon or Mars?
Change g: the Moon is about 1.62 m/s² and Mars about 3.71 m/s². A 70 kg person weighs about 686 N on Earth, roughly 113 N on the Moon and about 260 N on Mars — same mass, different weight.
Sources and last check
Information, not professional advice.