Acceleration Calculator — Using Force and Mass (F = ma)
Apply Newton's second law to find the acceleration of an object: enter the net (resultant) force in newtons and the mass in kilograms and get the acceleration in m/s² and as a multiple of g. Negative force gives deceleration.
N
kg
Net acceleration from Newton's second law: a = F / m
- 1
Net force and mass
F = 100 N, m = 10 kg = 100 N - 2
Acceleration a = F ÷ m
100 ÷ 10 = 10 m/s²Newton's second law rearranged: a = F / m.
How does this calculator work?
Newton's second law: a = F / m. Enter the net force in newtons and mass in kilograms to get acceleration in m/s². A 100 N force on a 10 kg mass gives a = 10 m/s² (≈ 1.02 g). Negative force gives deceleration. Assumes constant mass and a single resultant force.
Formula
How this is calculated
Newton's second law of motion states that the net force acting on an object equals its mass times its acceleration: F = ma. Rearranged, the acceleration is a = F/m. The "net" force is the vector sum of all forces acting — push, pull, friction, gravity — and its direction determines the direction of acceleration. A positive result means the object accelerates in the direction of the net force; a negative result means it decelerates.
The standard SI units are newtons (N) for force, kilograms (kg) for mass, and metres per second squared (m/s²) for acceleration. For context, the calculator also expresses the result as a multiple of standard gravity g = 9.80665 m/s², and shows the force as a fraction of the object's own weight (m × g) — useful for sizing motors, springs or braking systems.
This formula assumes the mass is constant (no fuel burn, no relativistic effects) and that the net force is the true resultant including all friction and drag. In practice, real-world friction, air resistance and variable force make this a first approximation — accurate for rigid bodies at low speeds where these assumptions hold.
Frequently asked questions
A net force is the vector sum of every individual force acting on the object simultaneously. If a car engine pushes with 3000 N forward and friction resists with 500 N backward, the net force is 2500 N forward — and a = 2500/mass.
Yes. Enter the net force as a negative number (opposing the direction of motion) to get a negative acceleration (deceleration). For braking, a typical car decelerates at around −5 to −8 m/s² under hard braking.
One newton (N) is defined as the force that gives a 1 kg mass an acceleration of 1 m/s². In imperial units, 1 pound-force ≈ 4.448 N.
TG we-Calculate Editorial Team. (2026). Acceleration Calculator — Using Force and Mass (F = ma) [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/acceleration-using-force-and-mass-calculator
TG we-Calculate Editorial Team. "Acceleration Calculator — Using Force and Mass (F = ma)." TG we-Calculate. 2026. https://we-calculate.com/calculator/acceleration-using-force-and-mass-calculator.
TG we-Calculate Editorial Team, "Acceleration Calculator — Using Force and Mass (F = ma)," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/acceleration-using-force-and-mass-calculator
@misc{wecalculate_acceleration_using_force_and_mass_calculator, title = {Acceleration Calculator — Using Force and Mass (F = ma)}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/acceleration-using-force-and-mass-calculator}}, year = {2026}, note = {TG we-Calculate} }
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