Newtons to Pounds-Force

Newtons and pounds-force

The newton is the SI unit of force: the force that accelerates one kilogram at one meter per second squared. Physics, engineering, load ratings and climbing gear (in kN) use newtons.

A pound-force is the weight of one pound under standard gravity: exactly 4.4482216152605 newtons. US engineering, rocket thrust and spring and load ratings use pounds-force (lbf).

Worked example

Convert 100 N: 100 × 0.2248089431 = 22.48089431, so 100 newtons is 22.48089431 pounds-force. Likewise 200 N = 44.96178862 lbf.

Estimating in your head

Divide by 4.4 for a quick figure; it is off by about 1.1%. For 100 N that gives 22.7 lbf, against 22.4809 exactly.

Going the other way

To convert pounds-force to newtons, divide by 0.2248089431 (or multiply by 4.44822161526). The swap button between the boxes opens that page.

lbf = N × 0.2248089431

1 N = 1 N and 1 lbf = ≈ 4.448221615 N, both by definition, so the factor is their ratio: 0.2248089431 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.