Inch-Pounds to Foot-Pounds Converter

About the Inch-Pounds to Foot-Pounds Converter

This converter handles the straight imperial torque change from inch-pounds to foot-pounds. It is useful when a manual or spec sheet uses one imperial unit and your wrench, chart, or habit uses the other.

The relationship is fixed at 12 inch-pounds per foot-pound, so the conversion itself is simple. The rest of the page shows the related torque units, including newton-meters, kilogram-force centimeters, and ounce-inches, so you can compare the same spec in the range that makes most sense for the job.

Use it for fastener work on cars, bikes, small engines, and similar maintenance tasks where the only real question is which torque scale the documentation used. It is also handy when a service manual lists smaller cover bolts in inch-pounds but the rest of the job is discussed in foot-pounds, or when you want to sanity-check a torque wrench setting before tightening a part that is easy to strip or crack.

When This Page Helps

A factor-of-12 unit mistake is easy to make when the spec and the wrench are both imperial. This page keeps inch-pounds and foot-pounds aligned, shows the same torque in several secondary units, and gives enough context to check that the setting on the wrench actually matches the fastener spec you are trying to follow.

How to Use the Inputs

1. Select direction: Inch-Pounds -> Foot-Pounds or the reverse.
2. Enter the torque value in the input field.
3. Adjust decimal precision with the second input.
4. Use a preset button for common torque values.
5. Read the primary and all secondary conversions in the output grid.
6. Consult the quick reference table for common in·lb -> ft·lb -> N·m values.
7. Expand the common application torques section to compare your spec with typical values.

Example Calculation

Tips & Best Practices

• The conversion factor is exact: 1 ft·lb = 12 in·lb. No rounding is involved.
• Most torque wrenches under 250 in·lb are calibrated in inch-pounds; above that, they switch to foot-pounds.
• For very small torques (under 10 in·lb), ounce-inches may be more appropriate - 1 in·lb = 16 oz·in.
• Always torque fasteners in the sequence specified by the manufacturer, especially on cylinder heads and wheels.
• Click-type torque wrenches should be stored at their lowest setting to preserve calibration spring life.
• If a spec says "snug" without a torque value, it typically means 5-7 ft·lb (60-84 in·lb) for small bolts.

Understanding Imperial Torque Units

Torque measures a twisting force and equals force multiplied by the lever arm distance. In imperial units, a foot-pound is one pound-force applied at the end of a one-foot lever; an inch-pound uses a one-inch lever. The factor of 12 between them comes directly from the 12 inches in a foot. Both are commonly used in US automotive, aerospace, and manufacturing settings.

Choosing the Right Torque Wrench

Torque wrenches come in different ranges: micro (1-50 in·lb), small (20-250 in·lb), medium (10-150 ft·lb), and large (50-600 ft·lb). Using a wrench at the very bottom of its range reduces accuracy, so match the wrench to your specific torque requirement. For precision work, a digital torque wrench offers +/-1% accuracy versus +/-3-4% for click-type wrenches.

Common Torque Mistakes

The most dangerous conversion error is confusing in·lb with ft·lb - torquing to 50 ft·lb when the spec is 50 in·lb means applying 12× the intended force. Other pitfalls include torquing dirty or lubricated threads without adjusting the spec, reusing torque-to-yield bolts, and not following a star or cross tightening pattern on multi-bolt flanges.

Frequently Asked Questions

• How many inch-pounds are in a foot-pound?

  Exactly 12 inch-pounds equal 1 foot-pound. To convert ft·lb to in·lb, multiply by 12. To go the other way, divide by 12.

• When should I use inch-pounds instead of foot-pounds?

  Use inch-pounds for small fasteners that require low torque - typically under about 200 in·lb (about 17 ft·lb). Examples include electronics screws, bicycle bolts, and small-engine components.

• Can I use a foot-pound wrench for inch-pound specs?

  Not accurately. A foot-pound wrench typically starts at 10 ft·lb (120 in·lb), and resolution at the low end is poor. Use a dedicated inch-pound torque wrench for specs under 120 in·lb.

• What happens if I over-torque a bolt?

  Over-torquing can strip threads, stretch the bolt past its elastic limit, crack cast components, or crush gaskets. Any of these failures can compromise clamp load and cause joint failure in service.

• Is inch-pound hyphenated?

  In engineering notation, it is written as in·lb (with a center dot) or in-lb (hyphenated). "Inch-pound" is standard in prose. All forms refer to the same unit.

• How do I convert inch-pounds to newton-meters?

  Multiply inch-pounds by 0.112985. For example, 120 in·lb × 0.112985 = 13.558 N·m. You can also convert to ft·lb first (÷12) then to N·m (×1.35582).