Force Calculator
Calculate force instantly in your browser — the published formula, worked locally with no data sent anywhere.
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What this tool does
Calculate force instantly in your browser — the published formula, worked locally with no data sent anywhere. Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
How to use the Force Calculator
- Enter or select mass (kg).
- Enter or select acceleration (m/s²).
- Read the calculated result; change any measurement to compare alternatives.
Formula
Newton's second law: F = m × a. Weight on Earth is the special case a = g: W = m × 9.80665.
- mass
- Mass (kg)
- accel
- Acceleration (m/s²)
Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
Worked example
For force calculator, the following measurements illustrate the exact method: Mass (kg): 10; Acceleration (m/s²): 2.
Inputs
- Mass (kg)10
- Acceleration (m/s²)2
Result
- Force (N)20
- Force (lbf)4.5
- Weight of this mass on Earth (N)98.07
- Weight of this mass on Earth (lbf)22.05
Results explained
- Force (N)
- Force (N) from the formula above. Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
- Force (lbf)
- Force (lbf) from the formula above. Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
- Weight of this mass on Earth (N)
- Weight of this mass on Earth (N) from the formula above. Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
- Weight of this mass on Earth (lbf)
- Weight of this mass on Earth (lbf) from the formula above. Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
Frequently asked questions
Newton's second law: F = m × a. Weight on Earth is the special case a = g: W = m × 9.80665.
Mass is in kilograms and does not change with location; the force is the net force — friction and other opposing forces must be subtracted before applying F = ma to real motion.
Every field is labelled with its unit — enter values in exactly the labelled unit and read the result in the labelled output unit. Fields with a unit symbol also support the site-wide imperial/metric switch, which converts before the formula runs.
It uses double-precision arithmetic and the published constants and formulas named on this page. The last displayed digit may be rounded, and real conditions can differ from the idealized model described in the assumptions.
Yes. Every calculation runs entirely in your browser; nothing you enter is uploaded, stored or shared.