Pound-Feet to Newton-Meters Conversion Chart
| Pound-foot (lb-ft) | Newton-meter (Nm) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 1 lb-ft | 1.36 Nm | Small Drone Brushless Motor Dyno Torque Test | 1 × 1.355818 = 1.36 N·m |
| 5 lb-ft | 6.78 Nm | Outdoor Power Equipment Recoil Starter Bolt Spec | 5 × 1.355818 = 6.78 N·m |
| 10 lb-ft | 13.56 Nm | Automotive Automatic Transmission Pan Bolt Torque | 10 × 1.355818 = 13.56 N·m |
| 15 lb-ft | 20.34 Nm | Automotive Aluminum Valve Cover Bolt Fastening | 15 × 1.355818 = 20.34 N·m |
| 20 lb-ft | 27.12 Nm | Passenger Vehicle Differential Cover Bolt Spec | 20 × 1.355818 = 27.12 N·m |
| 25 lb-ft | 33.9 Nm | Motorcycle Rear Footpeg Mounting Bracket Bolt | 25 × 1.355818 = 33.9 N·m |
| 50 lb-ft | 67.79 Nm | Classic Muscle Car Cast Iron Intake Manifold Bolt | 50 × 1.355818 = 67.79 N·m |
| 75 lb-ft | 101.69 Nm | Light Truck Front Suspension Upper Control Arm Bolt | 75 × 1.355818 = 101.69 N·m |
| 80 lb-ft | 108.47 Nm | Standard Domestic Passenger Car Wheel Lug Nut Rating | 80 × 1.355818 = 108.47 N·m |
| 100 lb-ft | 135.58 Nm | Full-Size SUV and Pickup Wheel Stud Nominal Torque | 100 × 1.355818 = 135.58 N·m |
| 150 lb-ft | 203.37 Nm | Automotive Engine Main Bearing Cap Fastener Spec | 150 × 1.355818 = 203.37 N·m |
| 200 lb-ft | 271.16 Nm | Heavy Commercial Truck Wheel Hub Mounting Stud | 200 × 1.355818 = 271.16 N·m |
| 250 lb-ft | 338.95 Nm | Medium Duty Commercial Vehicle Axle Retaining Nut | 250 × 1.355818 = 338.95 N·m |
| 300 lb-ft | 406.75 Nm | Industrial Centrifugal Pump Shaft Coupler Nut | 300 × 1.355818 = 406.75 N·m |
| 500 lb-ft | 677.91 Nm | Heavy Agricultural Tractor Wheel Hub Clamping Bolt | 500 × 1.355818 = 677.91 N·m |
Pound-foot to Newton-meter Formula & Unit Definitions
The conversion from pound-feet to newton-meters derives directly from international physical standards: 1 avoirdupois pound-force equals exactly 4.4482216152605 newtons, and 1 international foot equals exactly 0.3048 meters. Multiplying these factors (4.448221615 × 0.3048) produces 1.3558179483314 N·m (~1.355818 N·m). To convert any torque value in pound-feet, multiply it by 1.355818.
Quick Estimation: Quick mental shortcut: To estimate newton-meters from pound-feet, add one-third (33%) plus another 2% to the pound-foot value. For example, 100 lbf·ft gives 100 + 33 + 2 = 135 N·m (exact: 135.58 N·m); 75 lbf·ft gives 75 + 25 + 1.5 = 101.5 N·m (exact: 101.69 N·m).
Pound-foot — lbf·ft
Imperial & US Customary- Standard imperial unit of rotational moment (1 pound-force applied perpendicularly at a 1-foot radius)
- Dominant specification across North American domestic automakers, aerospace, and heavy equipment
- Equivalent to 1.355818 newton-meters (widely referred to in workshop parlance as foot-pound)
Newton-meter — N·m
SI Coherent Metric- Official coherent SI unit of mechanical torque and moment of force (1 N·m = 1 joule per radian)
- Global standard for ISO automotive assembly, robotics actuators, and wind turbine gearboxes
- Directly scales with metric ISO bolt diameter and standard thread pitch dimensions
Frequently Asked Questions
Q.How do you convert pound-feet to newton-meters accurately?
Multiply the torque in pound-feet by 1.355818 (or divide by 0.737562). For example, 50 lbf·ft × 1.355818 = 67.79 N·m.
Q.What is the reverse conversion from newton-meters to pound-feet?
To reverse the calculation, use the Newton-Meters to Pound-Feet Converter where 1 N·m equals 0.737562 lbf·ft.
Q.Why do European torque wrenches display N·m while American tools show lbf·ft?
European standards strictly mandate SI coherent units (newton-meters), whereas North American automotive and aerospace manufacturing traditionally relies on imperial customary pound-feet.
Q.What is 100 lbf·ft in metric newton-meters?
100 pound-feet equals approximately 135.58 newton-meters (N·m), a standard tightening spec for pickup truck wheel lug nuts.