Convert Inch-Pound-Force to Joules

Convert Inch-Pound-Force (in·lbf) to Joules (J) instantly and accurately.

Inch-Pound-Force (in·lbf)
Joules (J)

Conversion Formula

J = in·lbf × 0.112984829

About Inch-Pound-Force

An inch-pound-force (in·lbf) is the work done by one pound-force through one inch - exactly 0.11298482902761670 J (= 1/12 ft·lbf). It is the dominant torque unit for small fasteners and precision instruments in the US: a #6-32 screw in aluminium is torqued to 4-6 in·lbf; a dental implant abutment screw to ~25-30 Ncm (2.2-2.7 in·lbf). Hobby servo motor torque is quoted in oz·in (1 in·lbf = 16 oz·in). Bicycle stem bolts are typically 4-6 Nm (35-53 in·lbf). 1 in·lbf = 0.11298 J = 1/12 ft·lbf = 11.298 Ncm.

About Joules

The joule (J) is the SI unit of energy, defined as one newton acting through one metre (1 J = 1 N·m = 1 kg·m²/s²). Named after James Prescott Joule, whose 1840s paddle-wheel experiments established the mechanical equivalent of heat (~4.15 J = 1 calorie). One joule is modest: it lifts a 100 g apple by 1 m, heats 0.239 mL of water by 1°C, or powers a 1 W LED for 1 second. Daily adult resting metabolism is ~6-9 MJ. 1 J = 1 W·s = 0.23901 cal = 9.4782 × 10⁻⁴ BTU = 2.7778 × 10⁻⁷ kWh.

Quick Reference Table

Inch-Pound-Force (in·lbf)Joules (J)
1 in·lbf0.112985 J
2 in·lbf0.22597 J
5 in·lbf0.564924 J
10 in·lbf1.12985 J
25 in·lbf2.82462 J
50 in·lbf5.64924 J
100 in·lbf11.2985 J

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