Converter

Torque Converter

Convert between N·m, ft·lb, in·lb, kg·cm, and dyne·cm. Common presets for automotive, cycling, and mechanical work.

Quick Answer

1 N·m = 0.7376 ft·lb = 8.851 in·lb = 10.20 kg·cm. Car lug nuts: ~110 N·m (81 ft·lb). Use our converter for precise values.

N·m
100.000
ft·lb
73.7561
in·lb
885.073
kg·cm
1019.72
dyne·cm
1.0000e+9

About This Tool

The Torque Converter is an essential reference tool for mechanics, engineers, cyclists, and DIY enthusiasts who need to convert torque values between different unit systems. Torque, the measure of rotational force, is specified in different units depending on the industry, country, and application. This converter handles the five most common torque units: Newton-meters (N·m), foot-pounds (ft·lb), inch-pounds (in·lb), kilogram-centimeters (kg·cm), and dyne-centimeters (dyne·cm), providing instant bidirectional conversion with practical presets for common fastener applications.

Why Torque Conversion Matters

Torque specifications are critical for safe and reliable mechanical assembly. Every bolted joint, from wheel lug nuts on your car to the stem bolts on your bicycle, has a specific torque requirement determined by the manufacturer. Using the wrong torque can lead to catastrophic failure: an under-torqued wheel bolt can cause a wheel to detach at highway speed, while an over-torqued cylinder head bolt can crack the engine block. The complication arises because different manufacturers specify torque in different units. Japanese and European automakers use N·m, while American repair manuals often use ft·lb. Bicycle component manufacturers sometimes use N·m and other times kg·cm. Having a reliable converter eliminates guesswork and calculation errors.

Understanding Each Torque Unit

Newton-meters (N·m) are the SI standard unit for torque. One N·m is the torque produced by a force of one Newton acting at a perpendicular distance of one meter from the rotation axis. This is the internationally preferred unit and is increasingly adopted worldwide. Foot-pounds (ft·lb) are the traditional US unit, representing one pound-force applied at one foot from the pivot. Note that ft·lb of torque is sometimes written as lb·ft and should not be confused with ft·lbf (foot-pound-force of energy). Inch-pounds (in·lb) are used for smaller fasteners where ft·lb values would be inconveniently small fractions. Kilogram-centimeters (kg·cm) are a metric gravitational unit popular in Asian manufacturing and servo motor specifications. Dyne-centimeters are the CGS unit used in scientific research and precision measurements.

Torque in Automotive Applications

Automotive work is one of the most common contexts for torque conversion. Engine specifications list torque for dozens of fasteners, from cylinder head bolts (typically 40-90 N·m plus angle tightening) to intake manifold bolts (20-30 N·m), spark plugs (20-30 N·m for most), and oil drain plugs (25-45 N·m depending on vehicle). Suspension components like tie rod ends, ball joints, and strut mounting nuts each have specific torque requirements. Wheel lug nuts are perhaps the most safety-critical, typically ranging from 80 to 140 N·m. When working from repair manuals that use different units than your torque wrench, accurate conversion is not optional; it is a safety requirement.

Torque for Bicycle Maintenance

Modern bicycles, especially those with carbon fiber components, are extremely sensitive to torque specifications. Carbon handlebars, seat posts, and frames can crack from over-tightening. Common bicycle torque specs include: stem face plate bolts (4-6 N·m), handlebar clamp (5-7 N·m), seat post clamp (5-6 N·m), brake caliper mounting (6-8 N·m), crank arm bolts (12-14 N·m for Shimano Hollowtech), cassette lockring (40 N·m), and bottom bracket cups (35-50 N·m). A small preset torque wrench (2-20 N·m range) is an indispensable tool for any cyclist doing their own maintenance, and our converter helps when component manufacturers specify torque in units different from your wrench.

Torque vs. Tightening Angle

Some critical fastener applications use torque-plus-angle tightening, where the bolt is first tightened to a specified torque value and then rotated an additional number of degrees. This method provides more consistent clamping force than torque alone because it reduces the variability caused by friction differences between bolts. Cylinder head bolts on many modern engines use this method. For example, a specification might read: tighten to 40 N·m, then rotate an additional 90 degrees. The initial torque seats the bolt, and the angle turn stretches it to a precise preload. Our converter handles the torque portion of these specifications, while the angle is applied separately.

Frequently Asked Questions

How do I convert N·m to ft·lb?
To convert Newton-meters to foot-pounds, divide by 1.35582 (or multiply by 0.7376). For example, 100 N·m equals approximately 73.76 ft·lb. This conversion is one of the most common in automotive work, as European and Japanese cars specify torque in N·m while American mechanics and torque wrenches often use ft·lb. Our converter handles this bidirectionally, so you can enter either unit and see the equivalent in all five supported systems.
What is the difference between torque and force?
Force is a push or pull measured in Newtons or pounds-force, while torque is a rotational force measured about a pivot point. Torque equals force multiplied by the perpendicular distance from the axis of rotation (lever arm). A 10 N force applied 1 meter from a bolt creates 10 N·m of torque, while the same force at 0.5 meters creates only 5 N·m. This is why longer wrenches make it easier to loosen bolts: they increase the lever arm, multiplying the effective torque for the same applied force.
Why is proper torque important for bolts?
Under-torquing bolts can cause them to loosen from vibration, leading to structural failure, leaks, or component damage. Over-torquing can stretch or break the bolt, strip threads, crack castings, or crush gaskets. Proper torque creates the correct clamping force (preload) that holds the joint together. Critical applications like cylinder head bolts, wheel lug nuts, and structural connections have precise torque specifications. Always use a calibrated torque wrench for these applications and follow the manufacturer-specified values and tightening sequence.
What are common torque values for car lug nuts?
Car lug nut torque varies by vehicle but typically ranges from 80 to 140 N·m (59 to 103 ft·lb). Compact cars usually require 80-100 N·m, mid-size sedans 95-115 N·m, and trucks or SUVs 120-140 N·m. Always check your vehicle owner manual for the exact specification. Using the wrong torque can be dangerous: under-torqued lug nuts can cause wheels to come loose while driving, and over-torqued lug nuts can warp brake rotors, making braking unsafe. After any wheel change, re-torque after 50-100 miles of driving.
What is dyne·cm and when is it used?
Dyne-centimeter is a CGS (centimeter-gram-second) unit of torque. One dyne·cm equals 10^-7 N·m, making it an extremely small unit. It is used primarily in scientific research, particularly in rheology (the study of fluid flow), micromechanics, and precision instrument calibration. For example, the torque required to rotate a viscometer spindle in a fluid sample might be expressed in dyne·cm. While rarely encountered in everyday engineering, it remains important in laboratory settings and in older scientific literature that uses the CGS system rather than SI units.
How do I use a torque wrench correctly?
First, set the desired torque value using the wrench adjustment mechanism. Clean the bolt threads and apply lubricant if specified (dry vs. lubricated torque specs differ by 20-30%). Position the wrench perpendicular to the fastener and pull steadily (never push). When the wrench clicks (for click-type) or the beam reaches the target (for beam-type), stop immediately. For critical applications, tighten in stages (e.g., 50%, 75%, 100% of final torque) and follow any specified tightening pattern (typically star or cross pattern for multi-bolt flanges). Calibrate your torque wrench annually and store it at its lowest setting to preserve accuracy.