A torque converter translates between Newton-meters, pound-feet, pound-inches, kilogram-force meters, and dyne-centimeters. Torque is the rotational force used in engine specs, bolt tightening specs, and mechanical engineering — do not confuse torque (lb·ft) with energy (ft·lb), which have the same units but different meanings.
Torque Converter
Torque Reference Values
| Application | N·m | lb·ft | lb·in |
|---|---|---|---|
| Hand tightening (typical) | 2 | 1.5 | 17.7 |
| Bicycle pedal bolt | 35 | 25.8 | 309.7 |
| Car wheel lug nut (typical) | 100 | 73.8 | 885.1 |
| Truck lug nut | 150 | 110.6 | 1327.7 |
| V8 engine max torque (typical) | 400 | 295.0 | 3540.5 |
| High-performance engine | 700 | 516.3 | 6196 |
How to Convert Torque Units
Torque unit conversion is essential for mechanics, engineers, and DIY enthusiasts working with fastener specifications, engine performance data, and power tool settings. The most common conversion is between Newton-meters (N·m) used in metric specifications and pound-feet (lb·ft) used in US service manuals.
Step 1: Key Conversion Factors
1 N·m = 0.737562 lb·ft = 8.85075 lb·in = 0.101972 kgf·m. Going the other way: 1 lb·ft = 1.35582 N·m. Quick mental math: 100 N·m ≈ 74 lb·ft, 100 lb·ft ≈ 136 N·m. For kgf·m: 1 kgf·m = 9.80665 N·m (gravity × mass × distance).
Step 2: Torque vs Energy — Same Units, Different Concepts
Torque (lb·ft or N·m) and energy (ft·lb or J) have the same dimensional units but represent different physical quantities. Torque is a rotational force applied at a distance (force × distance from pivot). Energy (work) is a force applied over a linear distance. Context determines which interpretation applies — a wrench spec uses torque; a physics problem about falling objects uses energy.
Step 3: Using Torque Specs Correctly
Always torque fasteners to spec with a calibrated torque wrench. Over-torquing stretches bolts, cracks flanges, and can shear threads. Under-torquing causes loosening under vibration. For critical fasteners (cylinder head bolts, wheel lugs, brake calipers), follow the exact specification in the service manual — and re-torque after the first heat cycle where specified.
FAQ
How do I convert N·m to lb·ft?
Multiply N·m by 0.737562 to get pound-feet. Example: 100 N·m × 0.737562 = 73.76 lb·ft. Going the other way: multiply lb·ft by 1.35582 to get N·m. Example: 80 lb·ft × 1.35582 = 108.5 N·m.
What is the difference between lb·ft and ft·lb?
Pound-feet (lb·ft) and foot-pounds (ft·lb) are written differently but have the same value numerically. By convention, lb·ft is used for torque (a rotational force), while ft·lb is used for energy (work done). Since they are dimensionally equivalent, the converter applies to both.
What is kgf·m in torque?
Kilogram-force meters (kgf·m) measure torque using the force of gravity on a 1 kg mass. 1 kgf·m = 9.80665 N·m. This unit is common in older European and Japanese specifications. A torque spec of 10 kgf·m equals approximately 98 N·m or 72 lb·ft.
What is typical wheel lug nut torque in N·m?
Typical wheel lug nut torque is 80-120 N·m (59-89 lb·ft) for passenger cars, and 130-200 N·m (96-148 lb·ft) for trucks and larger vehicles. Always check your vehicle's service manual for the exact specification — overtightening can crack rotors and distort hubs.
Is this torque converter free?
Yes, completely free with no signup required. All conversions run instantly in your browser.