Force Converter
Convert between newtons, pound-force, kilogram-force, dynes, and poundals.
How force conversion works
Every force unit here converts through the newton — the SI unit of force, defined as the force needed to accelerate a 1 kg mass at 1 meter per second squared. 'Force' units built from a mass name (pound-force, kilogram-force) are technically defined using standard gravity, which is why they don't convert to newtons with perfectly round numbers.
The calculation has two steps: multiply your value by the number of newtons in the starting unit, then divide by the number of newtons in the target unit. The kilogram-force is exact by definition (1 kgf = 9.80665 N); the pound-force follows from it and the international pound.
Worked example
A strap is rated for 75 kgf and you need the figure in pound-force. First convert to newtons: 75 × 9.80665 = 735.49875 N. Then divide by the newtons in one pound-force (about 4.4482). The result is about 165.35 lbf.
Common conversions
| Conversion | Result |
|---|---|
| 1 lbf in newtons | 4.448222 N |
| 1 kgf in newtons | 9.80665 N |
| 1 N in pound-force | 0.224809 lbf |
| 1 N in kilogram-force | 0.101972 kgf |
| 1 N in dynes | 100,000 dyn |
| 1 poundal in newtons | 0.138255 N |
| 1 lbf in poundals | 32.174049 pdl |
Where each unit shows up
Newtons are the unit in physics, engineering calculations and SI datasheets. Pound-force appears in US specifications such as thrust ratings and bolt loads, while the kilogram-force survives on older tension gauges and in some load ratings. The dyne belongs to the small-scale CGS system and the poundal to an older absolute imperial system, so you will mostly meet those two in textbooks.
Pound-force and kilogram-force are gravitational units: they are tied to a fixed standard gravity, not to wherever the object happens to be, so the conversion factor never changes with location.
Frequently asked questions
What's the difference between pound-force and pound (mass)?
A pound (lb) measures mass, while pound-force (lbf) measures the force that gravity exerts on that mass at Earth's surface — they're related but not interchangeable, similar to how a kilogram measures mass while a kilogram-force measures the weight that mass produces.
Where is the poundal used?
It's a less common force unit from an older "absolute" imperial system that avoided referencing gravity — rarely seen in modern practice, but occasionally appears in older engineering textbooks and specifications.
How big is one newton in everyday terms?
About the weight of a 102-gram object, roughly a small apple, because 1 N divided by 9.80665 m/s² is about 0.102 kg.