Torque Unit Converter (N·m, ft·lb, in·lb)

Convert torque between newton metre (N·m), pound-force foot (ft·lb), pound-force inch (in·lb), newton centimetre (N·cm), kilogram-force metre (kgf·m) and kilogram-force centimetre (kgf·cm). Designed for mechanics, engineers, calibration labs and technical documentation.

Internally, every value is normalised to N·m using SI definitions for force and length, so that all unit conversions are consistent and traceable.

Torque unit converter

Engineering grade

The same value is converted into all supported units. Use the table on the right for a complete view.

Result

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Enter a torque value, select units and click “Convert”.

Normalised torque (base unit)

N·m: —

Torque in all supported units

Once you convert a value, this table shows the same torque expressed in every unit supported by the calculator. Values are rounded according to the selected number of decimals.

Unit Symbol Value Definition

Quick reference: N·m to ft·lb and in·lb

Typical tightening torques for automotive and mechanical work, expressed in N·m, ft·lb and in·lb.

N·m ft·lb in·lb

What is torque?

Torque is a measure of the tendency of a force to rotate an object about an axis. It is defined as the product of a force and a perpendicular distance from the axis of rotation:

Basic definition

\(\tau = F \cdot r\)

where \(\tau\) is torque, \(F\) is the applied force and \(r\) is the lever arm (moment arm) measured perpendicular to the force.

In SI units, force is measured in newtons (N) and distance in metres (m). The corresponding SI unit of torque is the newton metre (N·m).

Torque units supported by this converter

  • newton metre (N·m) – SI unit of torque.
  • pound-force foot (ft·lb) – common in automotive and mechanical specifications in the US.
  • pound-force inch (in·lb) – used for smaller fasteners, electronics and instruments.
  • newton centimetre (N·cm) – convenient for small torques.
  • kilogram-force metre (kgf·m) – legacy unit based on kilogram-force.
  • kilogram-force centimetre (kgf·cm) – smaller-scale version of kgf·m.

Key conversion factors (exact or standard)

  • 1 N·m = 0.7375621493 ft·lb
  • 1 N·m = 8.8507457916 in·lb
  • 1 N·m = 100 N·cm
  • 1 kgf·m = 9.80665 N·m
  • 1 kgf·cm = 0.0980665 N·m

Formulas used by the torque unit converter

The calculator uses N·m as an internal base unit. Every input is first converted to N·m, then distributed to all other units. This approach ensures internal consistency and cuts down rounding errors when chaining multiple conversions.

1. From arbitrary unit to N·m

Each unit \(u\) has an associated factor \(k_u\) such that:

\(\tau_{\text{N·m}} = \tau_u \cdot k_u\)

Example: for ft·lb, \(k_{\text{ft·lb}} = 1.3558179483\), so 50 ft·lb → 50 × 1.3558179483 ≈ 67.79 N·m.

2. From N·m to target unit

Once torque is expressed in N·m, conversion to any other unit \(v\) is:

\(\tau_v = \dfrac{\tau_{\text{N·m}}}{k_v}\)

Example: N·m → in·lb, with \(k_{\text{in·lb}} = 0.1129848290\). Then \(\tau_{\text{in·lb}} = \tau_{\text{N·m}} / 0.1129848290\).

Worked examples

Example 1 – 120 N·m to ft·lb and in·lb

  1. ft·lb: 120 × 0.7375621493 ≈ 88.51 ft·lb.
  2. in·lb: 120 × 8.8507457916 ≈ 1062.09 in·lb.
  3. N·cm: 120 × 100 = 12,000 N·cm.

Example 2 – 75 ft·lb to N·m and kgf·m

  1. N·m: 75 × 1.3558179483 ≈ 101.69 N·m.
  2. kgf·m: 101.69 ÷ 9.80665 ≈ 10.37 kgf·m.
  3. kgf·cm: 10.37 × 100 ≈ 1037 kgf·cm.

Example 3 – 15 kgf·cm to N·m and in·lb

  1. N·m: 15 × 0.0980665 ≈ 1.4710 N·m.
  2. in·lb: 1.4710 × 8.8507457916 ≈ 13.02 in·lb.
  3. ft·lb: 13.02 ÷ 12 ≈ 1.085 ft·lb.

Good practices when working with torque values

  • Always specify units in documentation and on drawings (e.g. “35 N·m” instead of just “35”).
  • Match your torque wrench units to the specification or convert carefully using a reliable converter.
  • Use appropriate resolution: over-precise values (e.g. 73.76291 ft·lb) are rarely meaningful in shop practice.
  • Distinguish torque from energy: even though N·m looks like joules, torque is not energy; context and notation matter.

This torque unit converter is designed as a practical tool for daily engineering work, combining user-friendly input with rigorous unit handling under the hood.

Frequently asked questions about torque units

Can I use this tool to convert torque wrench settings? ▾
Yes. Enter the value from your torque specification (for example in N·m) and convert it to the unit used by your wrench (for example ft·lb or in·lb). Always round to a sensible number of decimals and respect the wrench manufacturer’s operating range and calibration interval.
Why do some datasheets quote kgf·m instead of N·m? ▾
Kilogram-force metre (kgf·m) is a legacy unit based on gravitational force. Although SI recommends using N·m, kgf·m is still encountered in older drawings, Asian equipment and some translated manuals. This converter helps you translate those values into N·m and other modern units.
Is N·m the same as joule (J)? ▾
Dimensionally, both N·m and J can be expressed as kg·m²/s², but in engineering practice they represent different quantities: N·m is used for torque (a vector moment), while J is used for energy and work. For clarity, always write torque in N·m and energy in J, even though the units are dimensionally equivalent.
How many in·lb are in 1 ft·lb? ▾
1 ft·lb equals 12 in·lb, because 1 foot = 12 inches and the same pound-force is assumed in both units. The converter automatically uses this ratio to ensure consistency between ft·lb and in·lb values.
What precision should I use for engineering reports? ▾
For most mechanical applications, 1 to 2 decimal places in N·m or ft·lb is sufficient. High-precision calibration work may justify 3–4 decimals, but ensure that the instrument accuracy, environmental conditions and rounding rules support that level of detail. The decimal selector in this calculator allows you to match the output to your use case.