Enter values to see results
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N·m
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ft·lbf
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kgf·m
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in·lbf
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dyn·cm
Enter values to see results
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N·m
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ft·lbf
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kgf·m
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in·lbf
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dyn·cm
The Torque Conversion Calculator converts torque values between the most widely used engineering and scientific units: Newton-meters (N·m), foot-pounds (ft·lbf), kilogram-force meters (kgf·m), inch-pounds (in·lbf), and dyne-centimeters (dyn·cm). Torque — the rotational analogue of force — measures the tendency of a force to rotate an object about an axis and is defined as $$\tau = r \times F$$ where r is the moment arm and F is the applied force.
In the SI system, torque is expressed in Newton-meters. One Newton-meter equals the torque produced by a force of one Newton applied perpendicularly at one meter from the pivot. In the imperial system, foot-pounds (ft·lbf) dominate automotive and structural engineering, while inch-pounds (in·lbf) appear in fastener specifications and small-scale assemblies. The kilogram-force meter (kgf·m) remains common in older European technical literature and some Asian engineering standards. The dyne-centimeter, the CGS unit of torque, is used in laboratory physics and material science for very small torques.
The conversion relationships are anchored to the Newton-meter through exact or defined constants. Since 1 lbf = 4.4482216152605 N and 1 ft = 0.3048 m, $$1\ \text{ft·lbf} = 1.3558179483\ \text{N·m}$$ Similarly, 1 kgf = 9.80665 N (by definition), giving $$1\ \text{kgf·m} = 9.80665\ \text{N·m}$$ For inch-pounds, since 1 in = 0.0254 m, $$1\ \text{in·lbf} = 0.112984829\ \text{N·m}$$ And in CGS, 1 dyn = 10⁻⁵ N and 1 cm = 10⁻² m, so $$1\ \text{dyn·cm} = 10^{-7}\ \text{N·m}$$
Accurate torque conversion is critical in mechanical engineering. Automotive technicians must convert manufacturer torque specifications for bolts and fasteners between metric and imperial systems. Aerospace engineers work across unit systems when integrating components from international suppliers. Robotics designers convert motor torque ratings to match gear train calculations. Even in everyday tasks like bicycle maintenance or furniture assembly, correct torque values prevent both under-tightening (loose joints) and over-tightening (stripped threads or broken bolts).
This calculator instantly converts any entered value to all five units simultaneously, eliminating manual conversion errors and saving engineering time.
The calculator first converts the input value to Newton-meters (the SI base unit for torque), then converts from Newton-meters to every target unit:
Step 1 — Convert to N·m:
$$\tau_{\text{N·m}} = \tau_{\text{input}} \times k_{\text{to N·m}}$$
where k is the conversion factor for the selected input unit.
Step 2 — Convert from N·m to all units:
$$\tau_{\text{ft·lbf}} = \frac{\tau_{\text{N·m}}}{1.3558179483}$$
$$\tau_{\text{kgf·m}} = \frac{\tau_{\text{N·m}}}{9.80665}$$
$$\tau_{\text{in·lbf}} = \frac{\tau_{\text{N·m}}}{0.112984829}$$
$$\tau_{\text{dyn·cm}} = \tau_{\text{N·m}} \times 10^{7}$$
All five output values represent the same physical torque expressed in different unit systems. The Newton-meter value is the international standard and should be preferred in scientific publications. Foot-pounds are standard in American automotive and construction work — torque wrench settings for wheel lug nuts, engine head bolts, and structural connections are typically specified in ft·lbf. Inch-pounds are used for smaller fasteners (electronics enclosures, instrument screws). The kgf·m value is useful when working with older equipment or specifications from countries that historically used the gravitational metric system. Dyne-centimeters appear in physics research involving microscale torques.
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A typical wheel lug nut specification of 140 N·m equals approximately 103.3 ft·lbf. An American mechanic would set their torque wrench to about 103 ft·lbf to achieve the same clamping force.
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A 25 in·lbf fastener torque converts to about 2.82 N·m or 2.08 ft·lbf. This is a light torque typical for electronics enclosure screws or small mechanical assemblies.
Force is a push or pull measured in Newtons (or pounds-force), while torque is the rotational effect of a force about a pivot point. Torque equals force multiplied by the perpendicular distance from the force's line of action to the axis of rotation: τ = r × F. The key distinction is that torque depends on where the force is applied — the same force produces more torque when applied farther from the pivot. Torque is measured in Newton-meters (N·m), which dimensionally equals Joules but represents a different physical concept.
Both N·m and J equal kg·m²/s² dimensionally, but they represent different physical quantities. A Joule measures energy (a scalar), while a Newton-meter measures torque (a vector cross product). The SI explicitly reserves 'Joule' for energy and uses 'Newton-meter' for torque to avoid confusion. This is why you never see torque expressed in Joules even though the units are dimensionally identical.
Multiply N·m by 0.7376 to get ft·lbf, or multiply ft·lbf by 1.3558 to get N·m. For inch-pounds, multiply N·m by 8.8508 to get in·lbf. Most quality torque wrenches display both units, but when converting manually, always round to the nearest practical increment on your wrench scale. For critical applications (engine assembly, structural bolts), use exact conversion factors.
The dyne-centimeter is the CGS unit of torque, equal to 10⁻⁷ N·m. It appears in laboratory physics, rheology (measuring viscosity of fluids), and micromechanics where torques are extremely small. For example, the torque on a magnetic dipole in a weak field, or the rotational drag on microscopic particles in fluid, may be expressed in dyn·cm. Modern research increasingly uses SI (N·m or μN·m), but legacy literature and some instruments still use CGS units.
The kilogram-force meter is gradually being replaced by the Newton-meter, but it persists in several contexts. Some Japanese and Korean automotive specifications still list kgf·m alongside N·m. Older European machine tools, hydraulic equipment, and industrial documentation use kgf·m. The conversion is straightforward: 1 kgf·m = 9.80665 N·m. When encountering kgf·m values, multiply by 9.81 (approximately) to obtain N·m.
The conversion factors used here are exact or defined values. The pound-force is defined as exactly 4.4482216152605 N, the foot as exactly 0.3048 m, and the kilogram-force as exactly 9.80665 N (based on standard gravity). The dyne-cm conversion (10⁻⁷ N·m) is exact by definition of CGS units. Therefore, the conversions introduce zero rounding error — any imprecision comes only from the display precision of the calculator output.
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