Kilogram-force to newtons (kgf to N) converter

What is a kilogram-force to newtons converter?

A kilogram-force to newtons converter is an online tool that translates a force expressed in kilogram-force (kgf) into its equivalent in newtons (N), and back again. Both units measure force, but they belong to different traditions: the kilogram-force comes from the older gravitational (technical) system of units, while the newton is the coherent SI unit of force. Because the two are directly proportional, the conversion is a single multiplication, and this tool removes the risk of arithmetic mistakes when you move between engineering documents, datasheets, or textbooks that mix the systems.

How does the converter work?

Enter a number in either field and choose the unit you are working with. As soon as you type a value on one side, the converter instantly computes the matching value on the other side using the fixed relationship between kilogram-force and newtons. You can convert in both directions: kilogram-force to newtons, or newtons to kilogram-force. The unit selectors also let you switch to related force units such as pound-force (lbf) and kilonewtons (kN), so the same tool covers several common conversions without reloading the page.

The whole exchange rests on one definition. One kilogram-force is the force exerted by standard gravity on a mass of one kilogram, where standard gravity is defined as exactly 9.80665 m/s². Since force equals mass times acceleration, one kilogram-force equals one kilogram multiplied by 9.80665 m/s², which is 9.80665 newtons.

Formula for conversion

To convert from kilogram-force to newtons, multiply by the standard gravity constant:

$\text{N} = \text{kgf} \times 9.80665$

To convert from newtons back to kilogram-force, divide by the same constant (or multiply by its reciprocal):

$\text{kgf} = \frac{\text{N}}{9.80665} = \text{N} \times 0.101972$

Conversion table

The table below lists common kilogram-force values together with their newton equivalents, rounded for everyday use.

Examples

Example 1: Converting 1 kilogram-force to newtons

Take the base case of a single kilogram-force. Multiplying by the standard gravity constant gives:

$1 \text{ kgf} \times 9.80665 = 9.80665 \text{ N}$

So one kilogram-force is exactly 9.80665 newtons.

Example 2: Converting 10 kilogram-force to newtons

Suppose a hoist is rated for a pull of 10 kgf and you need the value in SI units for a calculation:

$10 \text{ kgf} \times 9.80665 = 98.0665 \text{ N}$

Example 3: Converting newtons to kilogram-force

Going the other way, convert 9.80665 N back to kilogram-force to confirm the relationship is reversible:

$9.80665 \text{ N} \times 0.101972 = 1 \text{ kgf}$

Example 4: Converting a larger newton reading

A load cell reads 100 N. To express this in the older gravitational units, divide by the constant:

$\frac{100 \text{ N}}{9.80665} = 10.1972 \text{ kgf}$

Notes

• The conversion factor 9.80665 m/s² is the internationally agreed value of standard gravity; it is a defined constant, not a measured one, so the conversion is exact.
• Local gravitational acceleration varies slightly with latitude and altitude. For most engineering work the standard value is used, but for very precise weighing the local value of g may matter.
• Kilogram-force should not be confused with the kilogram, which is a unit of mass. Force depends on both mass and acceleration, whereas mass is the same everywhere.
• The newton is the SI unit and should be preferred in scientific and modern engineering contexts; kilogram-force still appears in older datasheets, especially for tools, springs, and torque ratings.

Frequently asked questions

How many newtons are in 1 kilogram-force?

There are 9.80665 newtons in one kilogram-force. This number is the standard gravity constant in m/s², and because one kilogram-force is defined through it, the value is exact.

How do I convert newtons to kilogram-force?

Divide the number of newtons by 9.80665, or equivalently multiply by 0.101972. For example, 100 N divided by 9.80665 equals about 10.1972 kgf.

Is kilogram-force the same as a kilogram?

No. A kilogram is a unit of mass, while a kilogram-force is a unit of force equal to the weight of one kilogram under standard gravity. They share the same numerical “1” only because the kilogram-force is defined from a one-kilogram mass.

Why is the constant 9.80665 and not just 9.81?

9.80665 m/s² is the exact defined value of standard gravity adopted internationally. The rounded figure 9.81 m/s² is often used for quick mental estimates, but the precise constant should be used when accuracy matters.

Can I convert kilogram-force to pound-force with this tool?

Yes. The unit selectors include pound-force (lbf) and kilonewtons (kN) alongside kgf and N, so you can convert kilogram-force into any of these related force units in the same converter.

When would I still use kilogram-force today?

Kilogram-force remains common in older technical literature and in some mechanical fields, such as fastener torque specifications, spring ratings, and certain machinery datasheets, particularly where legacy documentation predates the widespread adoption of SI units.