Force Converter

How do you convert force units?

To convert a force, express it in newtons, then divide by the size of the unit you want. One newton is the force that accelerates a 1 kg mass by 1 m/s², and every other unit on this page is an exact multiple of it.

Step by step

1. Multiply the value by its unit’s size in newtons (1 lbf = 4.4482216152605 N, 1 kgf = 9.80665 N, 1 kN = 1,000 N, 1 dyn = 0.00001 N).
2. Divide that number of newtons by the target unit’s size in newtons.

Worked example: a 150 lbf pull converted to newtons is 150 × 4.4482216152605 = 667.2332 N. Going the other way, 700 N ÷ 4.4482216152605 = 157.3663 lbf. The pounds to newtons converter and the newtons to pounds converter run the same arithmetic for any value.

Mass is not force

Kilograms and pounds (lb) measure mass, the amount of matter in an object. Newtons and pounds-force (lbf) measure force, a push or pull. Weight is the force gravity puts on a mass: W = m × g. To keep the gravitational units exact, they use standard gravity, g = 9.80665 m/s², a fixed conventional value rather than the gravity at any particular spot on Earth.

That is why 1 kilogram-force is the weight of 1 kg at standard gravity, 9.80665 N, and why a 75 kg person weighs about 735.5 N. It also explains the “pounds” in this converter: they are always pounds-force (lbf), the weight of a 0.45359237 kg mass at standard gravity. Under standard gravity, a 1 lb mass weighs exactly 1 lbf, which is why the two are so often mixed up. For converting mass itself, use the weight converter.

What is a newton, and how big is it?

A newton (N) is the SI unit of force: the force that gives a 1 kg mass an acceleration of 1 m/s², so 1 N = 1 kg·m/s². It comes straight from the second law of motion, F = m × a. For a sense of scale, 1 N is about the weight of a 102 g object, such as a small apple, because 1 ÷ 9.80665 kg ≈ 101.97 g.

The BIPM SI Brochure (9th edition) lists the newton as a coherent derived unit. Since 2019 the kilogram has been defined by fixing the Planck constant at exactly 6.62607015 × 10⁻³⁴ J·s, so the newton now rests entirely on fixed constants of nature through the kilogram, meter and second.

Your weight in newtons depends on where you stand

Mass stays the same everywhere, but weight is m × g, and g varies. Earth’s surface gravity runs from about 9.780 m/s² at the equator to about 9.832 m/s² at the poles, a difference of about 0.53%, which is why gravitational units use the fixed conventional value of 9.80665 m/s².

A bathroom scale measures this force but displays mass, assuming standard gravity. The kgf to newtons converter turns a reading in kilograms-force into newtons.

Which force units are used where?

Newtons and kilonewtons are the standard in science and engineering worldwide, pounds-force remains common in US engineering and aerospace, and kilogram-force survives on older equipment, while dynes appear mainly in older physics texts.

• Newtons (N): the standard in physics, school science and engineering worldwide, and the unit on most load cells, force gauges and material test reports.
• Kilonewtons (kN): structural and civil engineering loads, anchor and bolt ratings, crane capacities and jet engine thrust outside the US. Climbing carabiners and slings are rated in kN; a 22 kN carabiner holds about 4,946 lbf. Pick kilonewtons in the converter at the top of this page to translate these ratings.
• Pounds-force (lbf): US engineering, aerospace (rocket and jet thrust), spring rates and pull tests. Pressure in psi is simply pounds-force per square inch; see the pressure converter.
• Kilogram-force (kgf): older European and Asian equipment, some fitness machines, scales and handgrip dynamometers. It is also called the kilopond (kp), a name still seen in older German technical documents.
• Dynes (dyn): the CGS unit, found in older physics texts and in surface tension values quoted in dyn/cm (1 dyn/cm = 1 mN/m).

Force also underlies other quantities. Multiply a force by a lever arm and you get torque, covered in the torque converter. Multiply it by a distance moved and you get work, measured in joules.

How are force, pressure, torque and work related?

Pressure is force divided by area, torque is force multiplied by a lever arm, and work is force multiplied by the distance moved, so each of these quantities is built from force units.

Worked example: a 500 N force pressing on 25 cm² (0.0025 m²) creates a pressure of 500 ÷ 0.0025 = 200,000 Pa, which is 2 bar. The same 500 N applied at the end of a 0.3 m wrench produces 150 N·m of torque, and pushing a load 0.3 m with it does 150 J of work: the same numbers, but different quantities with different meanings. Carry on with the psi to bar converter, the torque converter or the energy converter.