I have a vintage postal scale rated in ounce-force. How do I use it with modern equipment expecting newtons?

Multiply the ozf reading by 0.278 to get newtons. A 50 ozf reading = 13.9 N. If your modern system needs the reading in kilograms, divide further by 9.807: 13.9 ÷ 9.807 ≈ 1.42 kg.

My robot servo is rated at 60 oz·in stall torque. I need torque in N·m. How do I convert?

First convert oz·in to N·m: multiply by 0.00706155. So 60 oz·in × 0.00706155 = 0.424 N·m. This combines ozf-to-N (×0.278) and inch-to-metre (×0.0254) in one factor.

Are fishing line ratings ever given in newtons, or is ozf/lbf the only option?

Almost always imperial (lbf or ozf) in US and UK markets. European fishing gear sometimes shows the equivalent in kg (mass) or occasionally N. Converting ozf to newtons lets you compare across markets.

Why is the ozf-to-newton conversion factor 0.278?

It's derived from 1 ozf = 1/16 lbf, and 1 lbf = 4.4482 N. So 1 ozf = 4.4482 ÷ 16 = 0.27801 N. The decimal fraction reflects the 16-ounce-per-pound relationship.

Ounce-Force (ozf) to Newtons Converter

Enter a value to instantly convert between force units.

From

Precision4 dp

1 Ounce-Force = 0.278 Newton

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

N = ozf × 0.27801385095

Hobby servo motors, clock spring catalogs, postal scales, and fishing tackle in the US and UK are rated in ounce-force. When these products are used in projects where forces are calculated in SI units — robotics, mechatronics coursework, metric product design — converting ozf to newtons ensures the component fits the specification. A servo motor stall torque of 60 oz·in becomes meaningful in SI only after the force component is in newtons.

Source: NIST SP 811, Table B.8

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

Frequently Asked Questions

Real-World Examples

One ounce-force — 0.278 N, approximately the force of a 28.35 g calibration weight, a useful anchor for calibrating micro-force sensors.

1 ozf = 0.278 N

Sixteen ounce-force (= 1 lbf) — 4.448 N, the SI equivalent of one pound-force, confirming the consistency of the ozf and lbf conversion paths.

16 ozf = 4.448 N

A spring rated at 100 ozf — 27.8 N, entered into a mechatronics model to verify that the actuator force exceeds the spring preload.

100 ozf = 27.8 N

A 0.36 ozf actuator in a micro-robotics application — 0.1 N, matched against a 0.09 N grip-force requirement in a SI-unit design spec.

0.36 ozf = 0.1 N

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

Ounce-Force (ozf) to Newtons Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

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