Force Converter
Convert force between newtons, kilonewtons, meganewtons, pound-force, kilogram-force, and dynes.
How to use this tool
- Enter force and from unit in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your pound-force and the full breakdown beneath it.
Formula
All forces are normalised to newtons (N), then converted to each output unit:
N = value × factorfrom
Factors: 1 kN = 1,000 N, 1 MN = 1,000,000 N, 1 lbf = 4.44822 N, 1 kgf = 9.80665 N, 1 dyn = 0.00001 N.
How it works
The converter uses newtons as its SI base unit. The input is multiplied by its newton-equivalent factor to get a raw newton value, which is then divided by each output unit's factor. The kilogram-force factor of 9.80665 N is the standard gravitational acceleration, reflecting the force that one kilogram of mass exerts under standard Earth gravity.
Common mistake: Using kilograms as if they were a unit of force. Mass (kg) and force (N or kgf) are different physical quantities. A 10 kg object has a weight-force of about 98.0665 N on Earth, but in a zero-gravity environment that same 10 kg still has mass while exerting zero weight-force.
Worked example
Convert 1 newton to all force units
- Input: 1 newton. Newton is the pivot, so base = 1 N.
- kN = 1 / 1,000 = 0.001; MN = 1 / 1,000,000 = 0.000001.
- lbf = 1 / 4.44822 ≈ 0.22481; kgf = 1 / 9.80665 ≈ 0.10197.
- dyn = 1 / 0.00001 = 100,000.
1 N = 0.001 kN = 0.000001 MN = 0.22481 lbf = 0.10197 kgf = 100,000 dyn.
Common mistakes to avoid
- Using kilogram-force (kgf) and newtons interchangeably -- 1 kgf = 9.80665 N, not 1 N; a structural load rated in kgf must be multiplied by ~9.81 to get newtons.
- Confusing pound-force (lbf) with pound-mass (lbm) -- 1 lbf is the gravitational force on 1 lbm at standard gravity; in space where gravity differs, the force changes but the mass does not.
- Treating dynes as negligible -- 1 N = 100,000 dynes, so converting micronewton-level forces to dynes produces large numbers that look like errors but are correct.
Key terms
- Newton (N)
- The SI unit of force. One newton is the force required to accelerate a mass of one kilogram at one metre per second squared (F = ma).
- Pound-force (lbf)
- The force exerted by one pound of mass under standard gravitational acceleration (9.80665 m/s²), equal to approximately 4.44822 N. Used in US and Imperial engineering.
- Kilogram-force (kgf)
- The gravitational force on a one-kilogram mass at standard gravity, equal to exactly 9.80665 N. Sometimes written as 'kilopond' (kp) in older European literature.
- Dyne (dyn)
- The CGS unit of force, equal to 10⁻⁵ N. One dyne accelerates one gram at one centimetre per second squared. Still encountered in surface tension and older physics texts.
Frequently asked questions
- What is the difference between a newton and a kilogram?
- Kilograms measure mass; newtons measure force. At Earth standard gravity (9.80665 m/s2), a 1 kg object experiences a gravitational force of 9.80665 N (about 2.205 lbf). On the Moon, the same 1 kg mass experiences only about 1.62 N.
- How many newtons does a person weigh?
- A 70 kg person weighs 70 x 9.80665 = approximately 686.5 N (or about 154 lbf) at Earth surface.
- What is a dyne used for?
- The dyne is the CGS (centimetre-gram-second) unit of force, equal to 10^-5 N. It is still encountered in older physics literature, surface tension measurements (dynes/cm), and some material science contexts.