Inch-Pounds to Foot-Pounds Converter
Type in either unit and watch the other update instantly — plus a visual scale showing how your torque value compares to common bolts and fasteners.
What inch-pounds and foot-pounds actually measure
Both inch-pounds (in-lb) and foot-pounds (ft-lb) are units of torque — the rotational force applied to turn an object around a fixed axis, like tightening a bolt. The difference between them comes down to the length of the lever arm the force is measured over: an inch-pound is the torque produced by one pound of force at the end of a one-inch lever, while a foot-pound is that same one pound of force at the end of a twelve-inch (one-foot) lever. Since the lever arm is 12 times longer, the same applied force produces 12 times more torque in foot-pounds than in inch-pounds.
Both units also double as measures of work or energy, following the same basic physics — force applied over a distance — just describing a straight-line motion instead of a rotational one in that context.
The conversion formula
Inch-Pounds to Foot-Pounds
Foot-Pounds = Inch-Pounds ÷ 12
Example: 89 in-lb ÷ 12 = 7.42 ft-lb
Foot-Pounds to Inch-Pounds
Inch-Pounds = Foot-Pounds × 12
Example: 10 ft-lb × 12 = 120 in-lb
The factor of 12 is exact, not a rounded approximation, since it comes directly from the definition of a foot as exactly 12 inches. Any rounding in a displayed result is just a readability choice, not a limitation of the underlying math.
Why mechanics use both units — and why it matters
Smaller fasteners — spark plugs, valve covers, interior trim screws, and similar small-scale hardware — typically call for torque specs in the range of a few dozen to a couple hundred inch-pounds, a range where inch-pounds give far more useful precision than foot-pounds could. Larger fasteners like lug nuts, engine mounts, and structural bolts are usually specified in foot-pounds instead, since their torque requirements are large enough that foot-pounds keep the numbers in a cleaner, more manageable range. Many torque wrenches are dual-marked with both scales specifically because mechanics regularly need to move between small and large fasteners on the same job.
Getting the conversion right isn't just a math exercise — under-torquing a fastener risks it working loose over time, while over-torquing risks stripping threads, snapping the bolt, or warping the parts being clamped together. Manufacturer torque specs exist specifically to balance secure clamping force against the physical limits of the fastener and material, which is exactly why converting correctly between units matters in practice, not just on paper.
Common torque specs for reference
| Fastener | Typical Torque (in-lb) | Typical Torque (ft-lb) |
|---|---|---|
| Spark plug | ~180 in-lb | ~15 ft-lb |
| Valve cover bolt | ~106 in-lb | ~8.8 ft-lb |
| Oil drain plug | ~300 in-lb | ~25 ft-lb |
| Passenger vehicle lug nut | ~960–1,200 in-lb | ~80–100 ft-lb |
| Small electronics/trim screw | ~5–15 in-lb | ~0.4–1.25 ft-lb |
These are general reference figures, not a substitute for the specific torque specification listed in a manufacturer's service manual for your exact vehicle, component, or hardware.
More quick unit conversions
Working through torque specs often means juggling other unit conversions in the same project — measuring a bracket or clearance in the wrong unit system is just as common an issue as mixing up in-lb and ft-lb. The cm to inches calculator handles that exact kind of quick length conversion when a spec sheet or part is labeled in metric. And if you're weighing parts, tools, or shipping specs alongside your torque numbers, the kg to lbs calculator is a handy companion for keeping every measurement on the same page.
Inch-pounds to foot-pounds converter — FAQ
How do I convert inch-pounds to foot-pounds?
Divide the inch-pound value by 12: foot-pounds = inch-pounds ÷ 12. This works because a foot is 12 inches, and torque is force multiplied by lever-arm distance — so the same rotational force measured over a 12-inch arm instead of a 1-inch arm produces a value 12 times smaller in foot-pounds. For example, 89 inch-pounds ÷ 12 = 7.42 foot-pounds.
How do I convert foot-pounds to inch-pounds?
Multiply the foot-pound value by 12: inch-pounds = foot-pounds × 12. So 10 foot-pounds × 12 = 120 inch-pounds. This is simply the reverse of the inch-pounds-to-foot-pounds formula, since the two units differ by exactly that fixed factor of 12.
What's the actual difference between an inch-pound and a foot-pound?
Both measure torque — the rotational force applied around a fixed axis — but over different lever-arm lengths. An inch-pound is the torque produced by one pound of force applied at the end of a one-inch lever arm; a foot-pound is the same one pound of force applied at the end of a twelve-inch (one-foot) lever arm. Because the lever arm is 12 times longer, the same force produces 12 times more torque in foot-pounds than in inch-pounds.
Why do some torque wrenches use inch-pounds and others use foot-pounds?
Smaller fasteners — things like spark plugs, valve covers, and small electronics or interior trim screws — typically require torque specs in the range of a few dozen to a couple hundred inch-pounds, where inch-pounds give mechanics finer precision than foot-pounds could. Larger fasteners, like lug nuts, engine mounts, and structural bolts, are usually specified in foot-pounds because their torque requirements are large enough that foot-pounds keep the numbers in a more manageable range. Many torque wrenches are dual-marked with both scales for exactly this reason.
Why does getting torque specs right actually matter?
Under-torquing a fastener risks it loosening over time, which can cause a component to fail, rattle loose, or leak. Over-torquing risks stripping threads, breaking the bolt outright, or warping the parts being clamped together — all of which can cause damage that's more expensive to fix than simply using the correct torque value in the first place. Manufacturer torque specs exist specifically to balance secure clamping force against the physical limits of the fastener and material.
Is a foot-pound the same whether it's measuring torque or energy?
The unit itself is defined the same way — one pound of force acting over one foot of distance — but it's used to describe two different physical concepts depending on context. As a torque unit, it describes rotational force around an axis (like tightening a bolt). As a unit of work or energy, it describes linear force applied over a straight-line distance (like lifting a weight). The math is identical; only the physical situation being described differs.
How precise is this conversion?
The conversion factor of exactly 12 is exact, not an approximation, since it comes directly from the definition of a foot as exactly 12 inches. Any rounding you see in a result is purely a display choice for readability, not a limitation of the conversion itself.
