Convert between N·m, lbf·ft, kgf·m, ozf·in and more torque units.
Torque is a rotational force, the product of force and the perpendicular distance from the axis. The SI unit is the Newton-meter (N·m). In automotive engineering, pound-force foot (lbf·ft) is common in the US. Kilogram-force meter (kgf·m) is used in older engineering texts.
| Unit | In N·m |
|---|---|
| 1 lbf·ft | 1.35582 N·m |
| 1 lbf·in | 0.11298 N·m |
| 1 kgf·m | 9.80665 N·m |
| 1 kgf·cm | 0.09807 N·m |
| 1 ozf·in | 0.00706 N·m |
Torque is rotational force. The SI unit is Newton-metres (N·m). In the US, pound-feet (lb·ft) and pound-inches (lb·in) are common for automotive and fastener applications. Car engine torque (e.g., "400 lb·ft at 4,500 RPM") indicates pulling power at a given speed. Power and torque are related by P = τ × ω — an engine producing 300 lb·ft at 5,000 RPM generates approximately 285 horsepower.
| Unit | N·m | Use |
|---|---|---|
| 1 lb·ft | 1.35582 | US automotive specs |
| 1 lb·in | 0.11298 | Small fasteners |
| 1 kgf·m | 9.80665 | Older metric specs |
| 1 oz·in | 0.00706 | RC vehicles, small motors |
Torque and power are related but distinct. Torque is rotational force; power is how fast that force does work. A diesel truck engine produces massive torque (1,500–2,000 N·m) at low RPM for pulling heavy loads. A Formula 1 engine produces moderate torque but at extremely high RPM, generating over 700 kW. The formula is P (kW) = τ (N·m) × ω (rad/s) / 1000. A wrench applies torque; tightening it quickly means more power. This is why electric motors (peak torque at 0 RPM) accelerate faster off the line than combustion engines.
Torque (also called moment of force) measures rotational force — the tendency to rotate an object about an axis. The SI unit is the newton-metre (N·m). Other common units: pound-foot (lb·ft or ft·lb), pound-inch (lb·in), kilogram-force metre (kgf·m), and dyne-centimetre (dyn·cm). Conversions: 1 N·m = 0.7376 lb·ft = 8.851 lb·in = 0.10197 kgf·m. 1 lb·ft = 1.3558 N·m.
Car engine torque is specified in N·m (global) or lb·ft (US). A typical economy car produces 150–200 N·m; a performance sports car 400–600 N·m; a large diesel truck 1000–2000 N·m. Torque wrenches used in automotive and mechanical work are calibrated in N·m or lb·ft, sometimes both. Tightening a cylinder head bolt to 90 N·m (66 lb·ft) ensures correct clamping force without over-tightening.
| N·m | lb·ft | lb·in | kgf·m |
|---|---|---|---|
| 1 | 0.738 | 8.851 | 0.102 |
| 10 | 7.376 | 88.51 | 1.020 |
| 50 | 36.88 | 442.5 | 5.099 |
| 100 | 73.76 | 885.1 | 10.197 |
| 200 | 147.5 | 1770 | 20.394 |
Torque is the rotational equivalent of force — it is the product of a force and the perpendicular distance from the pivot point (moment arm). The SI unit is the newton-meter (N·m). Pound-feet (lb·ft) and pound-inches (lb·in) are standard in US automotive and mechanical engineering. The kilogram-force meter (kgf·m) appears in older European and Asian engineering standards. Converting torque units is essential when reading international engine specifications: a European engine rated at 400 N·m delivers approximately 295 lb·ft. Torque wrenches for automotive and industrial fastening are often sold with dual scales. The relationship between torque (T), power (P), and rotational speed (n in RPM) is P = T × n × 2π / 60, so knowing the torque and RPM allows calculation of shaft power output. Fastener tightening specifications in maintenance manuals are given in N·m or lb·ft depending on the manual's origin; using the wrong unit causes under- or over-torquing of critical hardware.
| Unit | N·m equivalent | Context |
|---|---|---|
| 1 lb·ft | 1.35582 | US automotive |
| 1 lb·in | 0.11298 | Small fasteners |
| 1 kgf·m | 9.80665 | Older European specs |
| 1 N·m | 1 | SI standard |
