I'm designing a structure in kN, but I need to specify a US bolt in lbf. How do I know the bolt is strong enough?

Convert your kN requirement to lbf: multiply kN by 224.81. For a 5 kN load, that's 1,124 lbf. Choose a bolt rated above 1,124 lbf with your required safety factor — typically 2× to 4× for structural connections.

My design spec is 50 kN. A supplier's datasheet says their cable is rated at 11,200 lbf. Does it work?

11,200 lbf × 0.004448 ≈ 49.8 kN — essentially equal to your 50 kN requirement. For safety, request a cable rated at least 10% higher: 12,300 lbf or 55 kN.

Is there a quick mental math for lbf to kN?

Divide by 225. For 2,250 lbf: 2,250 ÷ 225 = 10 kN. The exact factor is 224.81, so you're accurate to 0.1%.

Why do structural engineers in North America still use lbf when SI is standard?

Legacy codes, supplier catalogs, and equipment inventories. US construction standards (AISC, ACI, etc.) were developed in imperial units and still use lbf in many tables. Mixed-unit projects are now the norm in North American infrastructure.

Pound-Force (lbf) to Kilonewtons (kN) Converter

Enter a value to instantly convert between force units.

From

Precision4 dp

1 Pound-Force = 0.0044 Kilonewton

Key Formulas

Newton → Pound-Force

lbf = N × 0.224809

Pound-Force → Newton

N = lbf × 4.44822

Kilogram-Force → Newton

N = kgf × 9.80665

Newton → Kilogram-Force

kgf = N × 0.101972

Formula

kN = lbf × 0.0044482216153

US equipment catalogs — wire rope, anchor bolts, rigging hardware, hydraulic cylinders — publish working load limits and breaking strengths in lbf. When these components are specified into metric design projects, or when a US-sourced part must be verified against a kN-specified structural connection, converting lbf to kN is the essential step. A 2,000 lbf rope rated in a US catalog needs to be expressed in kN to compare against a metric engineering drawing.

Source: NIST SP 811, Table B.8

Last reviewed: 2026-06-11 · see our methodology

Frequently Asked Questions

Real-World Examples

Approximately 1 kN — a US bolt rated at 225 lbf tensile strength meets a metric structural drawing specifying a 1 kN minimum connection capacity.

225 lbf = 1 kN

A 10 kN load in lbf — the reverse anchor for checking whether a US supplier's 2,500 lbf rated cable meets a metric 10 kN design requirement.

2248 lbf = 10 kN

A US sling rated at 4,500 lbf working load limit — verified as 20 kN against the metric engineer's rigging calculation.

4500 lbf = 20.02 kN

A precision load cell rated at 100 lbf capacity — 0.445 kN, for entry into a metric calibration record alongside SI-unit sensor data.

100 lbf = 0.445 kN

newtons to lbf lbf to newtons kgf to newtons newtons to kgf kn to newtons newtons to kn

Pound-Force (lbf) to Kilonewtons (kN) Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

Related Converters