Acceleration due to Gravity Calculator

Use the acceleration due to gravity calculator to determine the value of g at Earth and other planets.

Weight at this gravity9.8067 N1 kg × 9.80665 m/s²

Force9.8067 N1 kg × 9.8067 m/s²

Force in pounds-force2.2046 lbf

Force in kilograms-force1 kgfthe mass that this force would weigh on Earth

Mass1 kg2.205 lb — mass, not weight

Acceleration9.80665 m/s²1 g

Acceleration in g1 gmultiples of standard gravity — what a pilot, a rider or an accelerometer reads

Force as a fraction of weight1×the same as the acceleration in g

Momentum gained per second9.8067 kg·m/sforce is the rate of change of momentum, which is Newton's second law in its original form

The formula

F = ma; weight = mg

Mass and weight are different quantities

Mass measures how much matter there is and how strongly it resists acceleration; it is the same everywhere. Weight is the force gravity exerts on that mass, so it changes with location — the same object weighs about a sixth as much on the Moon and nothing at all in free fall, while its mass is unchanged.

The confusion is built into everyday units. A bathroom scale reads in kilograms but measures force, and a "kilogram-force" is the weight of one kilogram under standard gravity — 9.80665 newtons. Pounds are worse, serving as both a mass and a force depending on context, which is why the pound-force has its own name.

Newton originally stated the second law as force being the rate of change of momentum, which is the more general form: it still holds when mass changes, as it does for a rocket burning fuel, where F = ma alone would mislead.