Force Calculator
Use Newton's second law, F = m × a, to find force, mass or acceleration in newtons, pounds-force or kilograms-force.
Answer
175 N
- In other units
- 175 N · 0.175 kN · 39.3416 lbf · 17.845 kgf
Force equals mass times acceleration.
Calculation breakdown
| Step | Formula | Result |
|---|---|---|
| Force in newtons | 70 kg × 2.5 m/s² | 175 |
How it works
Choose whether to find force, mass or acceleration, then fill in the other two.
Worked example
A 70 kg cyclist and bike accelerate at 2.5 m/s²:
- Force = 70 kg × 2.5 m/s² = 175 N
- In other units, that is about 39.34 lbf or 17.85 kgf
Net force
The force in F = m × a is the net force, the sum of every push and pull on the object. Friction and drag are included.
Sources
Frequently asked questions
What is the formula for force?
Force equals mass times acceleration, or F = m × a. A 70 kg mass accelerating at 2.5 m/s² needs a net force of 175 newtons. This is Newton's second law of motion.
What is a newton?
One newton is the force that gives a 1 kilogram mass an acceleration of 1 meter per second squared. So 1 N equals 1 kg·m/s². The calculator also shows pounds-force and kilograms-force.
How do you convert between newtons, pounds-force and kilograms-force?
One kilogram-force is exactly 9.80665 newtons, and one pound-force is about 4.44822 newtons. Pick the unit you want and the calculator converts for you.
How do I find mass or acceleration instead?
Choose what to find at the top. Mass is force divided by acceleration, and acceleration is force divided by mass. Mass must stay above zero, and acceleration cannot be zero when you solve for mass.
Is weight the same as mass?
No. Mass is the amount of matter, in kilograms. Weight is a force, the mass times gravity. A 1 kg mass at standard gravity weighs 9.80665 newtons, or 1 kilogram-force.