How to calculate force from mass and acceleration
Enter a mass and an acceleration, select their units, and click Calculate. The Force Calculator converts the values to kilograms and meters per second squared, applies F = m × a, and shows Force in newtons with equivalent values in lbf, kgf, and dyn.
- Enter a value in Mass (m), then choose a Mass unit.
- Enter a value in Acceleration (a), then choose an Acceleration unit.
- Click Calculate to show Force and Formula & steps.
- Click Copy result or Download result (.txt) to keep the text output.
- Click Reset to clear both values, restore the default units, and hide the result.
What the force formula calculates
Newton's second law multiplies mass by acceleration: F = m × a. The calculator converts each selected value before multiplying. A negative acceleration produces a negative Force result.
Mass (m): 10 Kilograms (kg)
Acceleration (a): 9.8 Meters per second squared
Force: 98 NFormula & steps lists the supplied values, any unit conversions, the formula, and the final multiplication. The result also shows lbf, kgf, and dyn equivalents.
Force Calculator units and input rules
- Mass unit offers Kilograms (kg), Grams (g), Pounds (lb), Slugs, and Metric tons (t).
- Acceleration unit offers Meters per second squared, Feet per second squared, and Standard gravity (g).
- Both fields are required. Mass must be greater than zero; acceleration may be negative, zero, or positive.
- Values use decimal notation with an optional leading minus sign. Scientific notation is rejected, and each value must have an absolute value no greater than
1e12.
Changing a value or unit hides the previous result. Click Calculate again to replace it. Invalid input hides the result and displays an error message.
What Force Calculator leaves out
The acceleration you enter is treated as net acceleration. The calculation does not add friction, drag, air resistance, gravity from another body, or vector components. It also does not fill in a missing value. To calculate weight, enter the mass and choose Standard gravity (g).
script.js calculates in the browser and makes no request that sends the inputs elsewhere. Copy result uses the page's clipboard helper. Download result (.txt) creates a text file from the displayed result.
Where force calculations come up
For a worked example, enter 10 kg and 9.8 m/s^2. The Formula & steps output shows the conversion and multiplication behind 98 N.
For a unit check, enter a value in Pounds (lb) and a value in Feet per second squared (ft/s^2). The result keeps the newton and lbf equivalents together.
For weight, enter a known mass and choose Standard gravity (g). A negative acceleration keeps the sign you assigned to the direction.
Force Calculator or another science calculator?
Browse Science Calculators when the unknown is a physics, chemistry, electrical, optics, wave, fluid, gas, or radioactive-decay quantity. Choose Acceleration Calculator when acceleration must be found from a change in velocity and elapsed time.
Choose Density Calculator when the relationship is density, mass, and volume. Choose Work Calculator when the calculation needs force, displacement, and angle.
Frequently asked questions
What is the formula to calculate force from mass and acceleration?
The formula is F = m × a. The calculator converts the selected mass and acceleration before multiplying them.
How do I calculate force in newtons?
Enter Mass (m), choose a Mass unit, enter Acceleration (a), choose an Acceleration unit, and click Calculate. Force appears in newtons, followed by lbf, kgf, and dyn equivalents.
Can I use negative acceleration in Force Calculator?
Yes. Acceleration may be negative, zero, or positive. With a positive mass, a negative acceleration produces a negative Force result.
Does Force Calculator include friction or drag?
Force Calculator applies the net acceleration you provide. It does not model friction, drag, air resistance, or other added forces, so include those effects in the net acceleration before entering it.