Torque Converter

Torque can be expressed in many different forms.

Depending on the scale of the item and the amount of force required, it can be expressed in Newton-meters, foot-pounds, inch-ounces, Newton-millimeters or more.

The Torque Conversion Calculator makes easy and accurate work of making conversions from one scale to the other. No more accidental errors of transposition or mistakes in arithmetic.

Just input your existing measurement units and convert it instantly to your desired measurement units.

Torque is a rotation or angle that causes a change in rotational motion. The symbol for torque is T, the Greek letter tau.

How Torque Works

Imagine a plane taking off down a runway.

As long as the plane is steadily traveling down the runway, the measurement for torque equals force times distance. Now let the plane take off.

Torque is a measure of how much force causes an object to rotate about an axis. In this case the plane and its takeoff point.

It is the key factor of what causes the plane to gain angular acceleration. Torque is a vector quantity. Meaning, it has a magnitude (size) and a direction.

The direction of the torque vector depends on the direction of the force on the axis. (In this case, the thrust upwards.)

Formula For Torque

The torque equation is:

T = F · r · sinθ

Where:

Although both torque and energy can be expressed in Newton-meters, torque is not energy. Torque is a vector.

SI Units

The SI unit for torque is the Newton-meter.

Imperial Units

In Imperial units, the foot-pound is used. What is meant by that is the force of Earth's gravity on a one-pound object.

Measuring Torque

Measuring static torque in a linear system like a plane steadily rolling down a flat, frictionless runway is easy. Given the length of the radius, the torque can be found directly.

In a Rotating System

Now imagine taking off. The thrust of the engines directs the plane into the air. The takeoff point is the pivot.

There are several other factors, but we will ignore them for the present.

How hard the engine needs to push to keep the plane aloft depends on the distance from the pivot point.

In this case, we can pretend we have a Harrier Jump Jet and we are directing the thrust perpendicular to the runway.

The closer to that pivot point, the harder the engines have to work to thrust upwards. As you get farther away, the engines need not push as hard.

In practice, measuring torque in a rotating system isn't easy.

Electronic Torque Sensors

Electronic torque sensors work by direct or indirect measurement.

Direct measurement uses a torque flange to measure strain within the metal of a drive shaft.

Indirect measurement determines torque through measurement of the motor power at the converter.

Conversion between torque units usually requires a simple mathematical formula.

The easy way is to use a torque converter like this one. However, if you want to do it by hand, here is the formula for converting units.

Newton Meters to Foot Pounds

Foot-pound = Newton-meters x 1.36

Foot Pounds to Newton Meters

Newton-meter = foot-pounds x 0.738

Other units are equally simple calculations. If you're doing a torque calculation, just make sure all units of measurement are in the same system.

For example, make sure you measure distance in meters and force in Newtons to make your calculations, not Newtons and feet.

The U.S. standard foot-pound is increasingly less common in science and practical applications.

Almost all auto, aircraft, and manufacturing applications meant for global use now use SI Newton-meters.

For very large items with minimal movement, measurement in foot-pounds is nonsensical.

Imagine trying to measure torque on something very large (like a door) with an ant pushing the edge. A smaller unit of measure makes sense.

Good news! Your answer will still be correct. The torque conversion calculator is accurate to eight decimal places.

However, if you are still finding understanding torque difficult, there are several references that may help you.

Of course, seek your instructor's guidance first. Other good places for help include:

• your local university faculty
• your local librarian
• a local tutor

You may find online references helpful. Free lessons are available. Use your favorite search engine and try these websites:

• Khan Academy
• University of Guelph- Department of Physics
• YouTube

For more practical examples, many mechanics depend on articles and charts published in magazines like:

• Auto Express
• Linear Motion Tips
• Engineers Edge

We hope these tips and our easy torque converter have been useful to you. Save this conversion calculator to the home screen of your smartphone, for quick and easy access to it.

For other downloadable calculators, check out physics, and mathcategories.