Gram-force (gf)

CGS & old metricTraditional unit (still used in some regions)

Exactly 0.00980665 newtons. Used for small forces, such as those of delicate sensors and instruments.

1 gram-force = 0.00980665 newtons (exactly).

About the gram-force

Where the kilogram-force suits cables and machines, the gram-force suits fine work. It is a thousandth of a kilogram-force, which makes it exactly 9.80665 millinewtons, and it is the pull of Earth on a one-gram mass under conventional gravity. Small forces such as the contact load of a delicate sensor or the draw of a light spring have often been quoted in grams-force in older specifications.

The origin of the number lies in an 1887 decision by the international weights and measures committee to define a standard value for gravity, corrected to sea level at 45 degrees latitude, built on a measurement made in 1888 at the Bureau in Paris. The 1901 General Conference rounded that to 980.665 cm/s2. NIST tables do not list a plain gram-force, only gram-force per square centimeter at 98.0665 pascals. As a multiple of the dyne, one gram-force is 980.665 dynes. Like its larger relatives it has largely given way to millinewtons.

Sources: Wikipedia: Kilogram-force; Wikipedia: Standard gravity; NIST SP 811, Appendix B.8 conversion factors

Gram-force conversion chart

1 gram-force expressed in every other force unit:

More CGS & old metric units

• kilogram-force (force)
• dyne (force)
• tonne-force (force)
• erg (energy)
• kilogram-force meter (energy)
• erg per second (power)
• technical atmosphere (pressure)
• barye (pressure)

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