Inch-Pounds to Foot-Pounds Calculator

Inch-pounds to foot-pounds formula

A foot contains twelve inches. Torque is force multiplied by perpendicular distance, so a torque expressed with an inch lever arm uses a numerical value twelve times larger than the same torque expressed with a foot lever arm. Therefore, converting inch-pounds to foot-pounds requires division by twelve.

For the reverse direction, multiply foot-pounds by twelve:

For conversions involving other units, this calculator first converts the source value to newton-metres and then converts that base value into the selected destination unit. This factor-based method supports consistent conversion across imperial, SI, gravitational metric, and CGS torque units.

Complete operating instructions

1. Enter the torque value in the first field. Standard decimals, negative values, commas, and scientific notation are accepted.
2. Select the source unit. Choose inch-pound force for the main in-lb to ft-lb conversion.
3. Select the destination unit. Choose foot-pound force when you need ft-lb.
4. Review the live result displayed above the form. It updates as you type or change a unit.
5. Adjust precision, rounding, separator, and notation settings when your reporting rules require a specific format.
6. Use the copy, sharing, text download, or print controls to preserve the result.
7. For a list of measurements, open the batch converter, paste all values, and download the output as CSV or JSON.

Keyboard users can move through fields with Tab. Press Enter inside the main form to submit the server-side calculation. The live result does not require submission, making quick checks immediate.

What inch-pounds and foot-pounds measure

Torque describes the turning effect of a force around an axis. It depends on both the applied force and the perpendicular distance from the axis. A force applied farther from the axis creates more torque than the same force applied closer to it.

An inch-pound force represents one pound-force acting through a perpendicular lever arm of one inch. A foot-pound force represents one pound-force acting through a lever arm of one foot. Since one foot equals twelve inches, twelve inch-pounds equal one foot-pound.

Torque and energy can share the same dimensional components, but their physical meanings differ. A foot-pound of torque describes a rotational tendency at an instant. A foot-pound of energy describes work completed through displacement. Torque values should normally include a force-oriented label such as pound-force foot, lbf·ft, or ft-lb of torque when ambiguity is possible.

Direction also matters. Positive and negative signs may identify clockwise and counterclockwise rotation, depending on the sign convention used by the engineer, manufacturer, or software system. The calculator preserves negative values so the direction information is not lost.

Step-by-step torque conversions

Example 1: Convert 144 in-lb to ft-lb

A torque of 144 inch-pounds is exactly 12 foot-pounds.

Example 2: Convert 75 in-lb to ft-lb

A torque of 75 inch-pounds equals 6.25 foot-pounds.

Example 3: Convert 10 ft-lb to in-lb

The reverse conversion uses multiplication because each foot-pound contains twelve inch-pounds.

Example 4: Convert 120 in-lb to newton-metres

Rounding to two decimal places gives approximately 13.56 N·m.

Example 5: Interpret a negative value

The magnitude is three foot-pounds, and the negative sign identifies the opposite rotational direction under the chosen sign convention.

Common conversion mistakes to avoid

Multiplying in the wrong direction: divide by twelve when converting inch-pounds to foot-pounds. Multiply by twelve only when converting foot-pounds to inch-pounds.

Confusing torque with pressure: inch-pounds are not pounds per square inch. The first is torque; the second is pressure.

Confusing mass with force: “pound” may describe mass in everyday language, but torque specifications generally use pound-force. Follow the notation stated by the equipment manufacturer.

Using excessive precision: a calculator can show many decimals, but the final answer should reflect the accuracy of the torque wrench, sensor, source measurement, and specification.

Ignoring direction: negative torque may be intentional. Do not remove the sign unless you only need magnitude and have documented that choice.

Applying the wrong specification: fastener torque varies with material, thread size, lubrication, coating, temperature, and manufacturer guidance. A correct conversion does not confirm that the selected torque is safe.

Where inch-pound and foot-pound conversions are used

Small fasteners, electronics, bicycles, firearms maintenance, appliances, automotive components, laboratory fixtures, and precision assemblies often specify torque in inch-pounds. Larger automotive, industrial, construction, and structural applications more often use foot-pounds or newton-metres.

A technician may own a torque wrench graduated in foot-pounds while the service manual lists inch-pounds. Converting the specification allows the technician to compare the requirement with the available tool. However, tool range matters: using a high-capacity wrench near the very bottom of its scale may produce poor accuracy. A properly ranged torque tool is preferable.

Engineers also convert units when reviewing drawings from different regions, comparing supplier documentation, validating test data, or entering specifications into software that expects a different unit. Batch conversion helps when a complete torque schedule contains many fasteners or operating points.

This calculator is suitable for arithmetic conversion and reporting. It does not replace manufacturer procedures, calibration records, engineering judgment, or safety review.