Newton's second law tool

Force Calculator

Solve force, mass, or acceleration from two known values using F = m × a.

Enter two known values

Solve a force problem

Free tool
N

This is the value being calculated.

kg

Amount of matter in the object.

m/s²

Change in velocity per unit time.

Use kilograms for mass, meters per second squared for acceleration, and newtons for force.

Try an example:

Your force result will appear here

Choose the missing variable and enter the other two known values.

Newton's second law

What is force?

Force is a push or pull that can change an object's motion. The net force on an object equals its mass multiplied by its acceleration.

Formula

Force formula

ForceF = m × a

  • F is net force in newtons.
  • m is mass in kilograms.
  • a is acceleration in meters per second squared.

Worked example

A 10 kg object accelerates at 3 m/s²

  1. Write the formula: F = m × a.
  2. Substitute the values: F = 10 × 3.
  3. Calculate the force: F = 30 N.

Rearranged equations

Solve for mass or acceleration

Mass

m = F ÷ a

Divide force by non-zero acceleration.

Acceleration

a = F ÷ m

Divide force by a positive mass.

Net force

Use the combined force on the object

Newton's second law uses net force, which is the vector sum of all forces. Forces acting in opposite directions should use opposite signs before they are combined.

Direction

Interpret positive and negative values

A positive or negative force indicates direction relative to the chosen axis. Because mass is positive, force and acceleration point in the same direction.

Units

Standard SI units

One newton equals one kilogram meter per second squared. Convert grams to kilograms and other acceleration units to meters per second squared before using the calculator.

One newton1 N = 1 kg·m/s²

Assumptions

What the calculation represents

  • Force should represent the net force.
  • Mass must be greater than zero.
  • Direction signs must be used consistently.
  • The calculation uses SI units without automatic conversion.

Related tools

Use the Acceleration Calculator to calculate acceleration from initial velocity, final velocity, and time.

Use the Rate of Change Calculator for general change-over-interval calculations, and review the Tables and Graphs Guide when presenting force and acceleration data.

Questions and answers

Calculator FAQ

How is force calculated?

Force is calculated by multiplying mass by acceleration using Newton's Second Law: Force = Mass × Acceleration.

What is Newton's Second Law of Motion?

Newton's Second Law explains that an object's acceleration depends on the net force applied and its mass.

What is the SI unit of force?

The SI unit of force is the newton (N), which is equal to one kilogram meter per second squared.

Enter two known values

Solve a force problem

Free tool
N

This is the value being calculated.

kg

Amount of matter in the object.

m/s²

Change in velocity per unit time.

Use kilograms for mass, meters per second squared for acceleration, and newtons for force.

Try an example:

Your force result will appear here

Choose the missing variable and enter the other two known values.

Calculator guide

How this calculator works

Force Calculator determines the net force acting on an object using mass and acceleration. It helps physics students, engineers, and laboratory users analyze motion, mechanical systems, and interactions based on Newton's Second Law.

Formula explanation

Force is calculated using Newton's second law, F = ma, where mass and acceleration determine the applied force.

Formula

Force = Mass × Acceleration

Worked example

Example: A 5 kg object accelerating at 2 m/s² experiences a force of 10 N.

Assumptions

  • Mass and acceleration values are measured accurately.
  • Input values use compatible units.
  • The calculation represents the net force acting on the object.

Examples

  • Example: Calculate the force required to accelerate an object when its mass and acceleration are known.
  • Example: Engineers analyze vehicles and machines by calculating forces involved in mechanical movement.

Common mistakes

  • Using incorrect mass units.
  • Confusing weight with force.
  • Ignoring acceleration direction.

Variables

  • Mass of object
  • Acceleration
  • Net force
  • Applied force
  • Measurement units

Limitations

  • Does not include complex force interactions in advanced systems.
  • Results depend on accurate mass and acceleration measurements.

Scientific references

  • OpenStax University Physics: Newton's Laws of Motion
  • NIST SI Units and Measurement References
  • Classical mechanics principles

Content review

Reviewed by: ScienceCalcHub Physics Review Team | Last reviewed: 2026-08-30

Applications

  • Physics education
  • Engineering mechanics analysis
  • Laboratory experiments
  • Machine and motion studies

Frequently asked questions

How is force calculated?

Force is calculated by multiplying mass by acceleration using Newton's Second Law: Force = Mass × Acceleration.

What is Newton's Second Law of Motion?

Newton's Second Law explains that an object's acceleration depends on the net force applied and its mass.

What is the SI unit of force?

The SI unit of force is the newton (N), which is equal to one kilogram meter per second squared.

Accuracy and transparency

Created and maintained by our editorial team

This physics calculator is maintained by the ScienceCalcHub Editorial Team. Its calculation logic is tested with representative inputs, while the supporting guidance is checked for formula clarity, units, assumptions, and common mistakes.

Written by
ScienceCalcHub Editorial Team
Reviewed by
ScienceCalcHub Scientific Review Team
Review standard
Formula accuracy, units, examples, and educational clarity

Learn more about our formula-review and correction process, explore our calculation methodology, or view our scientific references.

  • Calculation logic tested
  • Variables and units explained
  • Assumptions stated clearly
  • Corrections handled transparently