Torque Converter
Convert between newton-meters, foot-pounds, inch-pounds, and more
Torque conversions are essential for mechanical and automotive engineers who work with fastener specifications, engine performance data, and shaft design. A bolt torque specification might be given in N·m in one standard and ft·lb in another. Engine torque curves are published in different units depending on the manufacturer's country. Using the wrong units for torque calculations can result in under-tightened joints, overtorqued fasteners, or inaccurate power calculations.
Multi-Unit Converter
All conversions for 1 N·m
About Torque Units
The SI unit of torque is the newton-meter (N·m). Larger values use kilonewton-meters (kN·m). US engineering uses foot-pounds (ft·lbf) and inch-pounds (in·lbf). Metric-technical systems use kilogram-force meters (kgf·m). Converting correctly requires careful attention to which system a specification was written in.
History of Torque Measurement
Torque as a distinct physical quantity from force was formalized with the development of rotational mechanics in the 18th century. Early blacksmiths and machinists measured twisting force by the length of the wrench and the force applied, and the foot-pound unit naturally arose from this practice. The newton-meter became the SI unit as the metric system was formalized. Aerospace and automotive industries use torque units extensively, with different conventions in different countries. Torque wrenches with scales in both units are common in international garages and workshops.
Practical Tips for Torque Conversions
Torque is force × perpendicular distance — doubling the wrench length halves the force required. 1 N·m ≈ 0.738 ft·lb, or equivalently 1 ft·lb ≈ 1.356 N·m. For bolted connections, following the manufacturer's specification precisely is critical: under-torquing leads to loose joints, over-torquing causes yielding, bolt failure, or thread stripping. Angular torquing (tighten to a torque, then turn a specified additional angle) is often used for critical joints.
Common Pitfalls to Avoid
Confusing in·lb and ft·lb is a factor-of-12 error that can cause joint failures or over-torqued fasteners. Inch-pounds and foot-pounds are often both abbreviated 'lb', making specifications ambiguous. Mixing up torque and power (torque × angular velocity) is a common conceptual error in automotive and motor discussions. Applying static torque specifications to dynamic loading without a safety factor can lead to fatigue failure.
Professional Uses
Automotive technicians torque wheel lugs, head bolts, and suspension components to manufacturer specifications. Aerospace assemblers torque critical fasteners with calibrated tools and record values for traceability. Mechanical engineers specify torque in equipment datasheets for gearboxes, motors, and couplings. Industrial maintenance technicians torque bolted flange connections to prevent leaks. Cyclists adjust component torques for safety and performance.