Force Converter
Convert between newtons, kilonewtons, dynes, kilogram-force, pound-force, poundals, and more force units — for physics, engineering, and mechanics.
Quick Reference — 1 unit = ? Kilonewton (kN)
| Unit | Value |
|---|---|
| Newton (N) | 0.001 |
| Kilonewton (kN) | 1 |
| Meganewton (MN) | 1000 |
| Dyne (dyn) | 1e-8 |
| Kilogram-force (kgf) | 0.00980665 |
| Gram-force (gf) | 0.00000980665 |
| Pound-force (lbf) | 0.00444822 |
| Ounce-force (ozf) | 0.000278014 |
Formula
Multiply by (from factor / to factor) | F = m × a (Newton's second law)
Frequently Asked Questions
What is a newton, and how is it defined?
1 newton (N) is the SI unit of force, defined as the force needed to accelerate a 1 kg mass at 1 m/s² (F = m × a). It is named after Sir Isaac Newton. For everyday reference: an average apple weighs about 1 N under Earth gravity; a 1 kg bag of sugar weighs about 9.8 N; an adult human weighs roughly 700–800 N (70–80 kg × 9.8 m/s²).
What is the difference between mass (kg) and force/weight (N)?
Mass is the amount of matter in an object and never changes (measured in kg). Weight is the force gravity exerts on that mass (measured in newtons): Weight (N) = mass (kg) × gravitational acceleration (9.80665 m/s² on Earth). A 10 kg object weighs 98.07 N on Earth but only about 16.2 N on the Moon (1/6th gravity). "Kilogram-force" (kgf) is a non-SI unit that confusingly uses a mass unit name to express a force — 1 kgf = 9.80665 N exactly, by definition.
How do you convert pound-force (lbf) to newtons?
1 lbf = 4.44822 N. To convert lbf to N, multiply by 4.448. To convert N to lbf, divide by 4.448 (or multiply by 0.2248). Pound-force is common in US engineering specs: bolt torque ratings, rocket engine thrust (e.g. the Saturn V first stage produced 7.5 million lbf = 33.4 million N), and tensile strength of materials (often given in lbf or psi = lbf/in²).
What is a dyne, and where does it come from?
1 dyne = 10⁻⁵ newtons — a unit from the older CGS (centimetre-gram-second) system, defined as the force needed to accelerate a 1-gram mass at 1 cm/s². It is tiny: a dyne is roughly the weight of a mosquito. Dynes still appear in some older physics, chemistry, and surface-tension literature (e.g. surface tension is often quoted in dynes/cm), but the newton has replaced it in modern SI-based science and engineering.
What is the difference between a poundal and a pound-force?
These are easily confused but very different: 1 pound-force (lbf) = the weight of a 1-pound mass under standard gravity = 4.448 N. 1 poundal (pdl) = the force needed to accelerate a 1-pound mass at 1 ft/s² = 0.138255 N — about 32.17 times smaller than a pound-force (since standard gravity ≈ 32.17 ft/s²). The poundal belongs to the foot-pound-second (FPS) absolute system, which is rarely used today outside of historical British engineering texts.
How much force do everyday and industrial activities involve?
Reference force benchmarks: a human bicep curl: ~100–300 N. A car engine's peak piston force: several thousand N. A small drone's thrust: 5–20 N per motor. A commercial jet engine at takeoff: 100,000–400,000 N (100–400 kN) of thrust per engine. A car crash at 50 km/h into a wall can generate peak forces over 50,000 N on the occupant restraint system. Structural bolts are often rated by tensile force capacity in kN — a standard M12 bolt typically handles around 50–70 kN before failure.