Newtons, kgf and lbf
Mass and force are different things: a mass of 1 kg weighs 1 kgf under standard gravity (9.80665 m/s²), which is 9.80665 N. The pound-force is the weight of 1 lb: 0.45359237 × 9.80665 = 4.4482216 N.
- N and kN: SI units; structural loads, anchors and climbing gear (carabiners are rated in kN).
- lbf: US specs for winches, springs, actuators and thrust.
- kgf: scales, load cells and older equipment specs; 1 kgf = 9.80665 N.
- tf (tonne-force): hydraulic presses and cranes; 1 tf = 9.80665 kN. dyne: the old CGS unit, 10⁻⁵ N.
1 lbf = 4.4482216152605 N 1 N = 0.224809 lbf
1 kgf = 9.80665 N (exact) 1 N = 0.101972 kgf
1 kN = 101.972 kgf = 224.809 lbf
lbf to N and kgf table
| lbf | N | kgf |
|---|---|---|
| 1 lbf | 4.4482 | 0.45359 |
| 5 lbf | 22.241 | 2.268 |
| 10 lbf | 44.482 | 4.5359 |
| 20 lbf | 88.964 | 9.0718 |
| 50 lbf | 222.41 | 22.68 |
| 100 lbf | 444.82 | 45.359 |
| 200 lbf | 889.64 | 90.718 |
| 500 lbf | 2,224.1 | 226.8 |
| 1,000 lbf | 4,448.2 | 453.59 |
| 2,000 lbf | 8,896.4 | 907.18 |
| 5,000 lbf | 22,241 | 2,268 |
| 10,000 lbf | 44,482 | 4,535.9 |
Worked example
A climbing carabiner rated at 24 kN holds 2,447.3 kgf, or 5,395.4 lbf. A 2,000 lb winch line pull is 8.896 kN.
Frequently asked questions
How many newtons is 1 lbf?
1 lbf = 4.44822 N; 1 N = 0.224809 lbf.
How many newtons is 1 kgf?
1 kgf = 9.80665 N, the weight of 1 kg under standard gravity.
How many lbf is 1 kN?
1 kN = 224.809 lbf = 101.972 kgf.