A force converter changes a push or pull from one unit into another — newtons to pound-force, or kilogram-force to newtons. Force is what changes an object's motion, and it is distinct from mass: a 1 kg object has the same mass everywhere but exerts a different weight force on the Moon than on Earth. This tool covers newtons, kilonewtons, kilogram-force, pound-force, ounce-force and dyne.
The formula. Every value passes through the newton, defined as the force that accelerates 1 kg at 1 m/s². The factors are 1 kN = 1,000 N, 1 kgf = 9.80665 N (the force standard gravity exerts on 1 kg), 1 lbf = 4.448222 N, 1 ozf = 0.278014 N and 1 dyne = 0.00001 N. The relationship to mass is F = m × a, which is why kilogram-force carries the standard gravity value inside its factor.
Worked example. A 70 kg person standing still presses down with 70 × 9.80665 = 686.5 newtons, which is 70 kgf or about 154.3 lbf. A spring rated at 50 N holds roughly 5.1 kg against gravity. And 1 kN — a common structural figure — is about 102 kgf or 224.8 lbf.
Where it's used. Structural and mechanical engineering work in newtons and kilonewtons; spring, clamp and fastener ratings appear in lbf or kgf; and materials testing reports breaking loads in kN. The dyne survives mainly in older physics texts and surface-tension measurements. The common trap is treating kgf as a mass — it is a force, equal to the weight of that mass under standard gravity of 9.80665 m/s².