Nm to ft-lbs Converter

How to Convert Nm to ft-lb

The exact conversion factor between newton metres and foot-pounds is defined by the SI and imperial unit relationships:

• 1 foot = 0.3048 metres (exact)
• 1 pound-force = 4.4482216152605 N (exact)
• Therefore: 1 ft-lb = 0.3048 m x 4.4482216152605 N = 1.3558179483314 Nm
• And: 1 Nm = 1 / 1.3558179483314 = 0.7375621492772 ft-lb

In everyday use, the conversion is rounded to:

ft-lb = Nm x 0.7376 (6 significant figures: 0.737562)

Nm = ft-lb x 1.3558 (6 significant figures: 1.355818)

Worked Example

The default input is 100 Nm. To convert to ft-lb:

100 Nm x 0.737562 = 73.756 ft-lb

This matches the result shown in the calculator above. Reversing from 73.756 ft-lb: 73.756 x 1.355818 = 100.00 Nm.

When You Need This Conversion

Nm to ft-lb conversion is most commonly needed when:

• Your torque wrench is calibrated in ft-lb but your workshop manual specifies Nm (common when working on European or Japanese vehicles in the US, or vice versa).
• You are buying a torque wrench from an overseas supplier and need to match its range to your job requirements.
• Engine or transmission rebuild specifications in North American service manuals list values in ft-lb while your torque wrench reads in Nm.
• Comparing tightening torques across different brands or models that use different unit conventions.

Nm vs ft-lb: Which to Use?

Newton metres (Nm) are the SI unit of torque and are used by virtually all vehicle manufacturers and engineering standards outside North America, including all major NZ and Australian standards. Foot-pounds (ft-lb) remain common in the United States and in American-made equipment manuals.

Either unit can express the same physical quantity. A torque of 100 Nm and 73.76 ft-lb are exactly the same amount of twisting force. Your choice of unit should match your equipment and specification documents.

Accuracy Note

This converter uses the exact NIST-derived factor 0.73756214927727 ft-lb per Nm, rounded to 3 decimal places in the output. For most practical purposes (fastener torque, engine assembly, structural work), 3 to 4 significant figures is more than sufficient. High-precision laboratory applications should use the full 14-digit factor.

Related Calculators

• Torque Converter: convert between all torque units including Nm, ft-lb, in-lb, kgf-m, and more.
• Torque Calculator: calculate torque from force and distance (T = F x d).
• Torque to Horsepower Calculator: convert torque and RPM to horsepower or kilowatts.
• Bolt Torque Calculator: estimate required bolt tightening torque from bolt size and grade.
• Essential Calculators: browse all unit converters and tools.

Sources and method: Conversion factor from NIST Special Publication 811 (2008 Edition), Table B.8 torque conversions. 1 ft-lb = 1.355 817 948 331 4 Nm (exact per SI/imperial foot and pound-force definitions). National Institute of Standards and Technology, nist.gov.