One kilogram-force is 2.2046226218 pounds-force. The ratio is identical to the one between kilograms and pounds, because both units are defined by the same standard gravity — the gravitational term cancels out entirely.
About the units
Both are gravitational force units: the force exerted by a given mass under standard gravity of exactly 9.80665 m/s². The kilogram-force, or kilopond, comes from the metric gravitational system used in continental European engineering. The pound-force comes from the imperial equivalent. Since both multiply their respective mass by the same acceleration, the conversion between them reduces to the mass conversion, and the 2.2046226218 is exactly the kilograms-to-pounds figure. That cancellation is the neatest thing about an otherwise messy pair of units.
The exact factor
The exact value is 1 kgf = 2.20462262184878 lbf, from 1 kg = 2.20462262184878 lb. In newtons, 1 kgf is 9.80665 N and 1 lbf is 4.4482216152605 N, and dividing those gives the same figure. The practical consequence is that anyone who knows the kilogram-to-pound conversion already knows this one — no new number to memorise, which is unusual in force units.
Where you meet this conversion
Comparing older European machinery specifications against American ones, where one document gives kilopond and the other pounds-force for the same clamping force, spring rate or cable rating. Legacy equipment documentation, particularly from the 1950s to the 1980s, uses these units on both sides of the Atlantic. Physical therapy and strength testing equipment sometimes reports in kilograms-force. The conversion also appears in translated technical manuals where the original unit was left unconverted.