Force Conversion Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/10/2026
To convert a force, it is reduced to newtons, then converted into the target unit. A force of 100 newtons equals about 10.197 kilograms-force.
Explanation
The newton (N) is the SI unit of force, defined as the force required to give a one-kilogram mass an acceleration of one meter per second squared — it is the unit expected by virtually all modern physics and engineering formulas. The kilogram-force (kgf), more intuitive to many because it is directly tied to a familiar mass, represents the weight of a one-kilogram mass under standard Earth gravity: its value in newtons (9.80665 N) is therefore a fixed definition, not a measurement subject to variation. The pound-force (lbf), used in English-speaking countries (notably in the United States for tightening torques or engine thrust), follows the same principle with the pound as the reference mass unit. The dyne, finally, is the unit of force in the CGS system (centimeter-gram-second), now largely superseded by the International System but still encountered in some historical or specialized scientific contexts; its relationship to the newton (1 dyne = 10⁻⁵ N) follows directly from the definition of the CGS base units, with no measurement uncertainty. Once a force is expressed in newtons, it can be used directly in our weight calculator or our Newton's second law calculator to combine it with a mass or an acceleration.
Example: converting 100 N to kgf
Inputs
Value: 100. Starting unit: newtons. Target unit: kilograms-force.
Calculation
100 N equals 100 ÷ 9.80665 ≈ 10.197162 kgf.
Result
100 newtons equal about 10.197 kilograms-force.
Frequently asked questions
Why is the kilogram-force not an International System unit?
Because its definition depends on Earth's gravity (itself slightly variable by location), whereas the International System favors units independent of any local physical phenomenon. The kilogram-force nonetheless remains widely used in everyday contexts and some technical fields, notably for expressing tightening torques or loads, because of its intuitive link to a mass in kilograms.
Where is the pound-force still encountered today?
The pound-force remains commonly used in the United States and a few other English-speaking countries, particularly for expressing the thrust of an aircraft or rocket engine, or the tightening torque of a tool (often in pound-feet, lbf·ft). The rest of the world overwhelmingly uses the newton for these same purposes.
Should force and weight be distinguished in these conversions?
Weight is a special case of force (the force exerted by gravity on a mass), so the same force units apply. The important distinction is rather between mass (in kilograms, a quantity of matter) and weight or force (in newtons or kgf, a force): confusing the two is a frequent error, especially with the kilogram-force whose name recalls a mass unit.