Force Calculator
Use Newton's second law to find the net force on an object, or the mass or acceleration that goes with a force.
How to use the Force Calculator
- Choose the solve for.
- Enter the mass and pick its unit.
- Enter the acceleration.
- Choose the acceleration unit.
- Enter the force and pick its unit.
- Press Calculate. The result updates automatically as you type, and you can switch the result unit at any time.
About the Force Calculator
Newton's second law says the net force on an object equals its mass times its acceleration. "Net" is the key word: it is the total after all forces are added together, so a car cruising at constant speed has zero net force even though the engine is pushing hard, because drag and rolling resistance push back equally.
Use the formula to estimate the thrust or traction a vehicle needs, the force on a seat belt in a sudden stop, or the acceleration a given push will produce. Weight is just a special case: an object's weight is its mass times the acceleration of gravity, so a 1 kg mass weighs 9.81 N on Earth. In US customary units, one pound-force is the weight of a one-pound mass under standard gravity.
Formula
F = m × a m = F ÷ a a = F ÷ m
Force in newtons (N), mass in kilograms, acceleration in m/s². 1 N = 1 kg·m/s² ≈ 0.2248 lbf. Example: accelerating a 1,200 kg car at 3 m/s² takes 1,200 × 3 = 3,600 N (about 809 lbf) of net force.
Example calculation
Using the default values:
- Solve for = Force (F)
- Mass = 1200 kg
- Acceleration = 3
- Acceleration unit = m/s²
the calculator returns:
- Force: 3,600 N
- Acceleration in g: 0.3059 g
Frequently asked questions
What is a newton?
The force needed to accelerate a 1 kg mass at 1 m/s². It is about the weight of a small apple.
How do I convert newtons to pounds?
Multiply newtons by 0.22481 to get pounds-force. 100 N ≈ 22.5 lbf.
What is the difference between mass and weight?
Mass is the amount of matter (kg) and is the same everywhere. Weight is the force of gravity on that mass (N) and changes on the Moon or other planets.
Last updated: · Category: Science calculators