Grams-force to Pounds-force (gf to lbf)

1 gram-force equals 0.002204622622 pounds-force (rounded).

1 gram-force = 0.002204622622 pounds-force

How to convert grams-force to pounds-force

To convert grams-force to pounds-force, multiply the number of grams-force by 0.002204622622. The factor is rounded to 10 significant digits. To go the other way, multiply pounds-force by 453.59237.

pounds-force = grams-force × 0.002204622622

Example: 10 grams-force = 0.02204622622 pounds-force.

About these units

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.

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.

1 gram-force = 0.00980665 newtons (exactly).

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

Pound-force (lbf)

US & ImperialCurrent unit

Exactly 4.4482216152605 newtons: the weight of a one-pound mass under standard gravity. The US unit of force.

People have used the pound-force since the eighteenth century for low-precision work, long before anyone needed to define it carefully. A pound of material on Earth's surface pulls with about a pound of force, which made it convenient to treat the two as one. The twentieth century demanded a precise definition: one pound-force is the avoirdupois pound, exactly 0.45359237 kg, multiplied by standard gravity of 9.80665 meters per second squared, which comes to about 4.448 newtons.

Because the unit is not simply mass times acceleration in its own system, formulas in English engineering units need a conversion constant of about 32.174 pound-feet per pound-force second squared. A slug, 32.174049 pounds of mass, is what one pound-force accelerates at one foot per second squared. In the US, jet and rocket thrust is often given as pounds of thrust: each Space Shuttle solid rocket booster produced 3,300,000 pounds-force. Earth's gravity varies by up to about half a percent between equator and pole, which low-precision work can ignore.

1 pound-force = 4.448221615 newtons (approximately).

Sources: Wikipedia: Pound (force); NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

See all force units.