Torque Converter
Convert torque between N·m, kN·m, N·cm, kgf·m, lbf·ft, and lbf·in. Enter a torque value, then choose the units to convert from and to.
Convert Torque Between Units
Torque Conversion Formula
Where:
- \(T_{\mathrm{from}}\) — the entered torque value
- \(T_{\mathrm{to}}\) — the converted torque value
- \(f_{\mathrm{from}}\) — the number of N·m in one source unit
- \(f_{\mathrm{to}}\) — the number of N·m in one target unit
The calculator first converts the entered value to newton-meters, then divides by the factor for the selected target unit. This changes how the torque is expressed, not the physical torque itself.
Torque – Calculation Example
Example: convert the default value of 100 N·m to pound-force feet (lbf·ft). One lbf·ft equals 1.3558179483 N·m.
\[100\ \mathrm{N\cdot m}\times\frac{1\ \mathrm{lbf\cdot ft}}{1.3558179483\ \mathrm{N\cdot m}}\approx 73.7562\ \mathrm{lbf\cdot ft}\]
Result: 100 N·m is approximately 73.7562 lbf·ft.
How to use the calculator
- Enter a nonnegative number in Torque value. For example, enter 100 if a specification lists 100 units of torque.
- Choose the unit attached to that number in From unit. The default is newton-meter (N·m).
- Choose the unit you need in To unit. The default is pound-force foot (lbf·ft).
- Read Converted Torque, which shows the value and its target unit. Change either unit to make another conversion.
Both unit menus offer the same six choices: N·m, kN·m, N·cm, kgf·m, lbf·ft, and lbf·in. Selecting the same unit in both menus leaves the numerical value unchanged.
What torque means
Torque describes a force’s tendency to turn an object around an axis. Applying a force farther from the axis generally creates more torque: a long wrench makes it easier to turn a fastener than a short one when the same perpendicular force is applied. Torque is used in fastener specifications, motors, engines, gearboxes, and rotating equipment.
For a force applied at a distance from the rotation axis, torque magnitude is \(T=rF\sin\theta\), where \(r\) is the distance to the point of application, \(F\) is force, and \(\theta\) is the angle between the distance and force directions. The converter does not calculate torque from those measurements; it converts an existing torque value between units. If you need to convert a force value first, use the force converter.
Newton-meter (N·m) is the SI unit used for torque. Pound-force foot (lbf·ft) and pound-force inch (lbf·in) express torque using force in pounds-force and distance in feet or inches. Kilogram-force meter (kgf·m) uses kilogram-force, which is not the same as a kilogram of mass. Keep the force and distance parts of each unit together when reading a specification.
Conversion factors and practical limits
Each factor below gives the value of one unit in N·m. To convert to N·m, multiply by the factor. To convert from N·m, divide by it. The calculator uses these factors for every unit pair.
| Unit | 1 unit in N·m |
|---|---|
| Newton-meter (N·m) | 1 |
| Kilonewton-meter (kN·m) | 1,000 |
| Newton-centimeter (N·cm) | 0.01 |
| Kilogram-force meter (kgf·m) | 9.80665 |
| Pound-force foot (lbf·ft) | 1.3558179483 |
| Pound-force inch (lbf·in) | 0.112984829 |
Check the unit carefully before entering a number. In particular, N·cm is one-hundredth of an N·m, while kN·m is one thousand N·m. Confusing either with N·m can produce a substantial error. The menus do not include ounce-force inch, so a value given in that unit needs a separate conversion before it can be entered here.
The input accepts values of zero or greater. The displayed result is rounded to at most 10 decimal places, so very small nonzero results may appear as zero. For critical settings, follow the equipment manufacturer’s stated unit, tolerance, and rounding instructions rather than adding precision implied by a conversion.
Torque is related to rotational motion, but converting its units does not determine how quickly a shaft spins or how it accelerates. For other rotating-system quantities, see the moment of inertia converter or frequency converter.
Frequently Asked Questions
How do I convert between lbf·ft and lbf·in by hand?
Multiply lbf·ft by 12 to get lbf·in; divide lbf·in by 12 to get lbf·ft. The force stays the same, while one foot contains 12 inches. For example, 30 lbf·ft is 360 lbf·in. This shortcut applies only when the force unit is the same on both sides.
What is a normal or good torque value?
There is no universally good torque value. The appropriate setting depends on the fastener, materials, lubrication, and equipment design; an engine’s torque rating answers a different question from a bolt’s tightening specification. For assembly or maintenance, use the manufacturer’s specified value and tolerance rather than a general rule of thumb.
Can torque be negative?
Yes. A negative sign can indicate rotation in the direction opposite to the chosen positive direction, such as clockwise versus counterclockwise. This calculator accepts only nonnegative values, so convert the magnitude and retain the sign separately. A unit conversion does not change the torque’s direction.
Is ft·lb the same as lbf·ft?
In a torque specification, “ft·lb” commonly means pound-force foot (lbf·ft), although the wording can be ambiguous. A foot-pound can also be a unit of energy, which has the same unit dimensions but describes a different physical quantity. Check whether the specification refers to a turning effect or work done before interpreting or converting it.
Can I convert torque directly into horsepower or kilowatts?
Not from torque alone. Mechanical power also depends on rotational speed: \(P=T\omega\), where torque \(T\) is in N·m and angular speed \(\omega\) is in radians per second, giving power in watts. Two motors can produce the same torque but different power if they rotate at different speeds.
Can I treat a value in kilograms as kgf·m?
No. Kilograms measure mass, while kilogram-force measures force under standard gravity. A torque value in kgf·m also requires a lever-arm distance in meters. If a specification says only “kg,” it does not provide an unambiguous torque value; check the original documentation before entering it.
Does a torque-wrench extension change the required setting?
It can. An inline crowfoot or similar attachment can increase the effective lever length, so the torque at the fastener may differ from the wrench setting. An attachment positioned at 90° generally avoids that length change, though the tool’s instructions still apply. Unit conversion alone does not account for wrench geometry.
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