I need a replacement spring rated at 50 ozf. A metric supplier lists springs in kgf. What should I order?

50 ozf ≈ 1.42 kgf. Order a spring rated at 1.4–1.5 kgf to match the original. Check the spring rate (force per distance) to ensure both springs have similar stiffness. If comparing larger forces, see [lbf to kgf]({/force/lbf-to-kgf/}).

Why do imperial and metric markets rate precision instruments differently?

Historical adoption. US and UK industries standardized on pounds and ounces for force; Japan, Europe, and most of the world use kilograms-force. Both are intuitive in their regions and persist despite SI standardization.

Is kilogram-force (kgf) still used, or should I just learn newtons?

SI (newtons) is the modern standard, but kgf persists in automotive, industrial machinery, and Japanese engineering specs. When comparing equipment across markets, these conversions are essential for sourcing and verification.

Is there a quick mental math trick for ozf to kgf?

Roughly: 1 kgf ≈ 35 ozf. So divide ozf by 35 to estimate kgf. For example, 80 ozf ≈ 2.3 kgf. The exact factor is 0.0284, so you'll be accurate to within a few percent.

Ounces-Force (ozf) to Kilogram-Force (kgf) Converter

Enter a value to instantly convert between force units.

From

Precision4 dp

1 Ounce-Force = 0.0283 Kilogram-Force

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

kgf = ozf × 0.0283495

Light-duty precision instruments (springs, scales, load cells) may be rated in ounce-force (imperial standard) while Japanese or European equipment is specified in kilogram-force. When sourcing replacement springs, comparing postal scale capacities, or matching clamp forces across imperial and metric suppliers, this conversion bridges the gap.

Source: NIST SP 811, Table B.8

Frequently Asked Questions

Real-World Examples

1 pound-force (16 ozf) equals 0.454 kgf—the rough equivalence anglers and engineers remember: '1 lb ≈ half a kilogram-force.'

16 ozf = 0.454 kgf

A fishing line rated at 80 ozf (5 lbf or 5 lb test) equals roughly 2.3 kgf—useful when comparing to metric fishing rigs rated in kilogram-force capacity.

80 ozf = 2.27 kgf

A delicate clock spring rated at 1 ozf equals 0.0284 kgf—a tiny force in metric terms, but expressible in both unit systems when sourcing international replacement springs.

1 ozf = 0.0284 kgf

A 10 lbf postal scale (160 ozf capacity) equals roughly 4.54 kgf—a helpful conversion when comparing imperial scales to metric capacity specs.

160 ozf = 4.54 kgf

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

Ounces-Force (ozf) to Kilogram-Force (kgf) Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

Related Converters