Calculadora de Força
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
F = m·a
About this calculator
This force calculator allows you to determine the resultant force in newtons (N) from the mass of an object (in kg) and its acceleration (in m/s²). The formula used is Newton's second law: F = m × a. This law states that the force applied to a body is directly proportional to its mass and the acceleration it acquires.
To use the tool, simply enter the mass and acceleration values in the indicated fields. The calculator then multiplies these quantities and displays the result in newtons. It is important to note that the resultant force is a vector, but this calculator considers only the magnitude, assuming the force acts in the same direction as the motion.
This calculator is useful in various everyday situations and basic physics, such as calculating the force needed to accelerate a car, the force exerted by an engine, or even the force of gravity on an object. It can also be applied in engineering projects, education, and scientific experiments.
Care: Make sure to use consistent units (kg for mass and m/s² for acceleration). The formula assumes no other forces acting (such as friction or air resistance). In real situations, the calculated force may differ from the applied force due to these factors. Also, acceleration should be constant or instantaneous for accurate calculation.
Frequently asked questions
What is resultant force?
Resultant force is the vector sum of all forces acting on a body. In this calculator, we consider only one force causing acceleration, ignoring other forces like friction.
Can I use this calculator to find the weight of an object?
Yes, if you enter the mass and the acceleration due to gravity (approximately 9.8 m/s² on Earth), the result will be the weight in newtons.
What units should I use?
Use kilograms (kg) for mass and meters per second squared (m/s²) for acceleration. The result will be in newtons (N).
What if the acceleration is negative?
Negative acceleration indicates deceleration. The calculator will still work, and the result will be a negative force, indicating the force acts opposite to the direction of motion.
Does the calculator account for air resistance?
No, the formula F = m·a does not include air resistance or friction. In real situations, these factors can reduce the effective acceleration.