Force (lbf) Enter the applied force in pound-force (e.g., 50)

Lever Arm Length (ft) Enter the distance from pivot point in feet (e.g., 2)

Angle Between Force and Lever Arm (°) Enter the angle in degrees, 0 to 180 (e.g., 90)

Quick Examples:

Standard Wrench (90°) Angled Force (60°)

Calculate Clear

This calculator is for informational purposes only. Results are estimates based on ideal conditions and do not account for friction, material deformation, or dynamic effects. Consult engineering references for critical applications.

What Is Torque

Torque is a measure of rotational force. It tells you how much twisting force is applied when you push or pull on a lever arm at a distance from a pivot point. Think of using a wrench to tighten a bolt. The harder you push on the wrench handle and the longer the wrench, the more torque you create. Torque is measured in pound-feet (lb·ft) in the US customary system. Engineers and mechanics use torque values to make sure bolts are tight enough without being over-tightened.

How Torque Is Calculated

Formula

The formula multiplies three values together. First, take the force you apply. Then multiply by the length of the lever arm. Finally, multiply by the sine of the angle. The sine of an angle tells you how much of your force actually creates rotation. At 90 degrees, the sine equals 1, so all your force creates torque. At 0 or 180 degrees, the sine equals 0, so no torque is created. This is why pushing straight down on a wrench handle that is pointing up creates no rotation.

Why Torque Matters

Understanding torque helps you work with anything that rotates, from bolts and screws to motors and engines. Knowing the correct torque ensures connections are secure without being damaged by over-tightening.

Why Correct Torque Is Important for Mechanical Safety

Using the wrong torque can cause serious problems. Under-tightened bolts may come loose over time, leading to equipment failure or accidents. Over-tightened bolts can strip threads, break parts, or weaken the material. In cars, incorrect torque on wheel lug nuts can cause wheels to come off while driving. Following proper torque specifications helps prevent these dangerous situations.

For Automotive Work

Mechanics use torque specifications for nearly every bolt on a vehicle. Cylinder head bolts, wheel lug nuts, and suspension components all have specific torque values. Using a torque wrench ensures each fastener is tightened correctly. This prevents engine damage, wheel problems, and safety issues on the road.

For Construction and Engineering

Structural bolts in buildings and bridges must be tightened to exact torque values. Too little torque means the connection may slip under load. Too much torque can stretch the bolt beyond its limit. Engineers calculate the correct torque for each connection based on bolt size, material, and the loads it must carry.

Torque vs Force

Torque and force are related but different concepts. Force is a straight push or pull measured in pounds. Torque is a twisting force measured in pound-feet. A 50-pound force applied at the end of a 2-foot wrench creates 100 pound-feet of torque. The same 50-pound force applied directly to the bolt head with no lever arm creates zero torque. Understanding this difference helps explain why longer wrenches make it easier to turn tight bolts.

Example Calculation

A mechanic needs to tighten a bolt using a 2-foot long wrench. They apply 50 pounds of force perpendicular to the wrench handle (at a 90-degree angle). Let us calculate the torque produced.

The formula is T = F × r × sin(θ). First, convert the angle to radians: 90 degrees times π divided by 180 equals approximately 1.5708 radians. The sine of 90 degrees equals 1. Now multiply: 50 lbf times 2 ft times 1 equals 100 lb·ft.

Torque: 100.00 lb·ft

This torque value tells the mechanic how much twisting force is applied to the bolt. If the specification calls for 100 lb·ft, this is exactly right. If the specification is higher, the mechanic would need to apply more force or use a longer wrench. At 90 degrees, the full force creates rotation, giving the maximum possible torque for that force and lever arm length.

Frequently Asked Questions

Who is this Torque Calculator for?

This calculator is for mechanics, engineers, students, and DIY enthusiasts who need to calculate or verify torque values. It helps anyone working with bolts, wrenches, motors, or rotating equipment understand the relationship between force, distance, and angle.

Why does angle affect torque?

The angle determines how much of your applied force actually creates rotation. At 90 degrees, all your force goes into turning. At other angles, some force pushes along the lever arm instead of around the pivot. At 0 or 180 degrees, the force pushes straight along the arm and creates no rotation at all.

How do I convert torque to Newton-meters?

To convert pound-feet to Newton-meters, multiply the torque value by 1.3558. For example, 100 lb·ft equals approximately 135.58 Newton-meters. This conversion is useful when working with specifications from different countries or manufacturers.

Can I use this calculator for motor and engine torque?

This calculator works for static torque from a single force application. Motor and engine torque calculations involve rotational speed, power, and dynamic factors not included here. For rotating machinery, consult manufacturer specifications or engineering references for accurate values.