Force Converter
Convert between newtons, pounds-force, kilograms-force, dynes and kips.
How to use this calculator
- 1Enter the value you want to convert.
- 2Pick the unit you are converting from and the one you want.
- 3The table below shows the same value in every other supported unit.
How the calculation works
result = (value × factor(from) ) / factor(to)- factor
- How many newtons one unit represents
Every value is converted to newtons first, then out to the target unit. This means n units need n factors rather than n² conversion pairs.
The newton is defined from F = ma: one newton accelerates one kilogram at one metre per second squared. Everything else here scales from it.
Kilogram-force and pound-force are gravitational units — they express force as the weight of a given mass at standard gravity (exactly 9.80665 m/s²). This is why kgf converts to newtons by exactly that constant.
Mass and force are different quantities that share names in the imperial system. A "pound" can mean either pound-mass or pound-force, which is a persistent source of engineering error; this converter handles force only.
Worked example
100 pound-force to newton
- 1.One pound-force is 4.4482216 newtons, so 100 lbf is 444.82216 newtons.
- 2.One newton is 1 newtons, so divide: 444.82216 ÷ 1 = 444.82216.
- 3.Put another way, 1 lbf = 4.4482216 N.
Result: 444.82216 N
What this assumes, and where it stops
Assumptions
- Conversion factors follow the internationally agreed definitions of each unit.
Limitations
- Results are computed in double-precision floating point, which is exact to about 15 significant figures.
- Very large or very small values are displayed in scientific notation to avoid misleading precision.
Common questions
What is the difference between a pound and a pound-force?
A pound-mass is an amount of matter; a pound-force is the weight that mass has at standard gravity. They are numerically equal on Earth's surface, which is exactly why they get confused — but on the Moon a 1 lb mass still has 1 lb of mass while weighing about 0.17 lbf. In SI the distinction is built into the units (kilogram vs newton) and the confusion mostly disappears.
Why is a kilogram-force exactly 9.80665 newtons?
Because standard gravity is defined as exactly 9.80665 m/s² by international agreement — it is a defined constant, not a measurement. So a kilogram-force is exactly that many newtons by definition, with no rounding involved.
Formula and content last reviewed on .
Results are estimates for information only, not professional advice.
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