Force Converter
Force is a push or pull that changes an object's motion, measured in a variety of units across scientific, engineering, and commercial contexts. The SI unit is the newton (N), equal to the force needed to accelerate one kilogram by one metre per second squared. A newton is about the weight of a 100-gram object on Earth. Pound-force (lbf), the imperial unit, equals about 4.448 newtons and represents the gravitational force on one pound of mass. Kilogram-force (kgf) equals the gravitational force on one kilogram, approximately 9.80665 newtons. The dyne, an older CGS unit equal to one hundred-thousandth of a newton, persists in some scientific contexts. Ounce-force (ozf) is used in some specifications, while kiloponds (kp), poundals, and other units appear in specialized fields. Understanding force conversions is essential when reading equipment specifications, comparing loads, evaluating structural limits, or converting between measurement systems. A one-kilogram object weighs about 9.81 newtons at Earth's surface, or about 2.2 pound-force. This calculator displays nine force units for instant conversion.
NIST conversion factors
All conversions below use standard NIST-defined factors, with all units expressed relative to the newton.
| Unit | Symbol | Newtons |
|---|---|---|
| Newton | N | 1 |
| Kilonewton | kN | 1,000 |
| Meganewton | MN | 1,000,000 |
| Dyne | dyn | 0.00001 |
| Pound-force | lbf | 4.44822 |
| Kilogram-force | kgf | 9.80665 |
| Ounce-force | ozf | 0.27801 |
| Kilopond | kp | 9.80665 |
| Poundal | pdl | 0.138255 |
Force converter: frequently asked questions
What is the SI unit of force?
The newton (N) is the SI unit of force, defined as the force needed to accelerate one kilogram by one metre per second squared. One newton is roughly the weight of a 100-gram object. Force measurements are essential in engineering, physics, and many industrial applications.
What is pound-force?
Pound-force (lbf) is an imperial unit equal to about 4.448 newtons. It represents the gravitational force on one pound of mass at Earth's surface. It is commonly used in the United States for specifications like engine thrust or equipment weight limits.
What is the difference between mass and force?
Mass (measured in kilograms or pounds) is the amount of matter. Force (measured in newtons or pound-force) is what you need to move or accelerate that mass. Weight is the force of gravity on a mass: weight equals mass times gravitational acceleration (about 9.81 m/s² on Earth).
What is kilogram-force?
Kilogram-force (kgf) is a unit equal to the gravitational force on one kilogram at Earth's surface, approximately 9.80665 newtons. It is still used in some countries and technical fields, though the newton is preferred internationally.
Why are there so many force units?
Force units developed independently in different systems and countries. The metric system uses newtons. Imperial systems use pound-force. Some technical fields use kilogram-force or dyne. Converting ensures clarity when reading specifications or comparing equipment from different sources.
Official sources
- NIST Handbook 44: Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices.
- NIST Special Publication 330: The International System of Units.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.