Free Nm to ft-lbs Converter

Torque Conversion Between Newton-Meters and Foot-Pounds

This torque converter provides a simple way to switch between several common torque units, including newton-meters (Nm) and foot-pounds (ft-lbs), as well as kilogram-force centimeters (kgf-cm), joules per radian (J/rad), and kilogram-meters (kgm). Whether you are an automotive technician, a mechanical engineer, or a DIY enthusiast, understanding how to convert Nm to ft-lbs and vice versa is essential when working with torque specifications from different regions or tools.

What Is Torque?

Torque, often called the moment of force or rotational force, quantifies how effectively a force causes an object to rotate around a fixed pivot. The magnitude depends on both the applied force and the perpendicular distance from the pivot point to the line of action of the force. Mathematically, it is the product of force ($F$) and lever arm distance ($r$): $\tau = F \times r$. The SI unit for torque is the newton-meter (Nm), while the imperial unit commonly used in the United States and some other countries is the foot-pound (ft-lb). It is important to note that the foot-pound is a unit of torque, not a unit of force; do not confuse it with the pound-force (lbf), which measures linear force.

Key Conversion Factors

The foundation of any Nm to ft-lbs conversion lies in these two constant relationships:

• 1 Nm = 0.7376 ft-lbs
• 1 ft-lb = 1.3558 Nm

Armed with these factors, converting between the two systems becomes a simple multiplication or division.

Nm to ft-lbs Quick Reference Table

Common torque values in newton-meters and their equivalents in foot-pounds:

Newton-meters (Nm)	Foot-pounds (ft-lbs)
1	0.738
2	1.475
5	3.688
10	7.376
20	14.751
25	18.439
30	22.127
35	25.815
40	29.502
50	36.878
100	73.756

ft-lbs to Nm Quick Reference Table

Conversely, here are frequently encountered foot-pound values converted to newton-meters:

Foot-pounds (ft-lbs)	Newton-meters (Nm)
1	1.356
2	2.712
5	6.779
10	13.558
20	27.116
25	33.895
30	40.675
35	47.454
40	54.233
50	67.791
100	135.582

Practical Example: Using the Conversion

Suppose you are calibrating a dynamometer for a gear train. The required output torque is 12 ft-lbs, but the dynamometer displays readings only in newton-meters. To obtain the correct display value, multiply the given torque by the conversion factor:

$$12 \text{ ft-lbs} \times 1.3558 = 16.27 \text{ Nm}$$

Thus, the dynamometer should indicate approximately 16.27 Nm. Alternatively, you could use the converter’s built‑in calculation to get this result instantly.

Other Torque Units You Might Encounter

Beyond Nm and ft-lbs, several other units appear on torque wrenches and in engineering documentation.

Kilogram‑force centimeters (kgf-cm)
This unit is often written incorrectly as “kg-cm” (without the “f” suffix). The correct notation includes “f” to indicate kilogram‑force, which accounts for Earth’s gravitational pull ($g \approx 9.80665 \, \text{m/s}^2$). One kilogram‑force centimeter equals:

$$1 \text{ kgf-cm} = 0.09807 \text{ Nm} = 0.07233 \text{ ft-lbs}$$

Joules per radian (J/rad)
In the context of work and power calculations, torque can also be expressed in joules per radian. This unit is numerically equivalent to the newton‑meter:

$$1 \text{ J/rad} = 1 \text{ Nm} = 0.738 \text{ ft-lbs}$$

Kilogram‑meter (kgm)
Sometimes labeled as a kilopondometer, the kilogram‑meter (kgm) represents the torque produced by one kilogram of force acting at a one‑meter lever arm. Its conversion factor is:

$$1 \text{ kgm} = 9.80665 \text{ Nm}$$

Because the kilogram‑meter relies on the same gravitational constant, it is essentially a larger version of the kgf‑cm unit.

A Note About Notation

Proper notation matters when working with torque to avoid errors. The shorthand “kg-cm” is misleading; the correct symbol is “kgf-cm” to explicitly identify the use of kilogram‑force. Similarly, “foot‑pounds” (ft‑lbs) must not be confused with “pound‑force” (lbf), which is a measure of linear force rather than rotational torque. Using precise symbols helps ensure accurate communication and calculation in mechanical and engineering contexts.