Enter any two known values — mass, acceleration, or force — and the Force Calculator solves for the missing variable using Newton's Second Law (F = m × a). Choose your calculation type, pick your preferred units for each quantity, and get the result in the unit of your choice.
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Result in Newtons (N)
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The force formula comes from Newton's Second Law of Motion: F = m × a, where F is force in Newtons, m is mass in kilograms, and a is acceleration in meters per second squared. This equation means that a larger mass or greater acceleration both result in a larger force.
Net force is the vector sum of all individual forces acting on an object. If two forces act in the same direction, they add together. If they act in opposite directions, they partially or fully cancel out. The net force determines how an object accelerates according to F = ma.
Rearrange Newton's Second Law: a = F ÷ m. For example, if a 10 N force acts on a 2 kg object, the acceleration is 10 ÷ 2 = 5 m/s². Use the 'Calculate Acceleration' option in this calculator to do it automatically.
Yes, weight is a force — specifically, it is the gravitational force acting on an object's mass. It is calculated as W = m × g, where g is the acceleration due to gravity (approximately 9.81 m/s² on Earth). Weight is measured in Newtons, not kilograms.
Yes, force is a vector quantity, meaning it has both a magnitude and a direction. For example, a 20 N force pointing north is different from a 20 N force pointing east. In F = ma, both force and acceleration are vectors, while mass is a scalar.
When two forces act in the same direction on an object, they add together to produce a greater net force. For instance, two 10 N forces in the same direction result in a net force of 20 N, causing greater acceleration than either force alone.
Force and motion are directly linked through Newton's Second Law. A net force applied to an object changes its state of motion — it causes acceleration (a change in velocity). Without a net force, an object continues at constant velocity (Newton's First Law).
The SI unit of force is the Newton (N). Other common units include the kilonewton (kN = 1000 N), dyne (1 N = 100,000 dyn), kilogram-force (1 kgf ≈ 9.81 N), and kip (1 kip = 4448.22 N). This calculator lets you select and convert between several of these units.