Torque converter: foot lbs to inch lbs calculator (ft-lb to in-lb)
What are foot-pounds and inch-pounds?
Foot-pounds (ft-lb)
A foot-pound (ft-lb) is a customary unit of torque in the imperial and United States systems. It describes the turning effect of a one-pound force acting at a perpendicular distance of one foot from the axis of rotation. Foot-pounds are the default unit on American automotive specifications: engine output, lug-nut ratings, and suspension bolt values are almost always quoted this way.
Inch-pounds (in-lb)
An inch-pound (in-lb) is the smaller companion unit, produced by a one-pound force applied one inch from the pivot. Because a foot contains twelve inches, one foot-pound is exactly twelve inch-pounds. Inch-pounds are the practical choice wherever the torque is small — electronics, plastic housings, small machine screws, and instrument work — since a foot-pound figure would round away the precision those jobs need.
How does the calculator work?
The converter ties the two torque units together in a single pair of fields. Type a value into either box and the other one is recalculated immediately. The tool remembers which field you edited last and converts outward from it, so the pair never falls out of step no matter which direction you work in.
The arithmetic is an exact factor rather than an approximation. One foot-pound is twelve inch-pounds by definition of the foot, so converting foot-pounds to inch-pounds means multiplying by twelve, and going back means dividing by twelve.
Foot-pounds and inch-pounds conversion formulas
To convert foot-pounds to inch-pounds, multiply by the exact factor 12:
To convert inch-pounds back to foot-pounds, divide by 12:
Conversion table
The table below summarizes how the two torque units relate to each other.
| Torque unit | Foot-pounds (ft-lb) | Inch-pounds (in-lb) |
|---|---|---|
| 1 Foot-pound | 1 | 12 |
| 1 Inch-pound | 0.0833333 | 1 |
For the reverse direction as a dedicated page, see the inch-pounds to foot-pounds converter.
Examples
The following examples reuse the same numbers as the calculator’s test fixtures.
Example 1: Convert 1 ft-lb to inch-pounds
Starting from a single foot-pound:
So 1 ft-lb is exactly 12 in-lb.
Example 2: Convert 2.5 ft-lb to inch-pounds
A fractional value typical of light assembly work:
Thus 2.5 ft-lb equals 30 in-lb.
Example 3: Convert 60 in-lb to foot-pounds
Working in the other direction:
So 60 in-lb is exactly 5 ft-lb.
Practical applications
The conversion earns its keep at the torque wrench. Many wrenches are calibrated in only one of the two units, and a service manual may quote the other, so a mechanic converting 2.5 ft-lb to 30 in-lb can dial in a small-fastener spec on an inch-pound wrench without guesswork. Under-tightening leaves a joint loose; over-tightening strips threads or cracks castings.
Assembly and manufacturing documentation runs into the same split. Electronics enclosures, sensor mounts, and sheet-metal screws are specified in inch-pounds, while the chassis, engine, and drivetrain fasteners around them are specified in foot-pounds. Converting between the two keeps a single build sheet readable to everyone working from it.
Equipment comparison is a third use. Tool catalogs list cordless screwdrivers in inch-pounds and impact wrenches in foot-pounds, and putting both on one scale makes it obvious whether a tool actually covers the fasteners you intend to drive.
Frequently asked questions
How do I convert foot lbs to inch lbs?
Multiply the foot-pound value by 12. For example, 10 ft-lb × 12 = 120 in-lb.
How many inch-pounds are in a foot-pound?
Exactly twelve. One foot-pound equals 12 inch-pounds because a foot contains twelve inches and both units share the same one-pound force.
How do I convert inch-pounds back to foot-pounds?
Divide the inch-pound value by 12. For example, 60 in-lb ÷ 12 = 5 ft-lb.
Is the conversion factor exactly 12, or rounded?
Exactly 12. The foot is defined as twelve inches, so the ratio is exact and no rounding error is introduced by the conversion itself.
When should I use inch-pounds instead of foot-pounds?
Use inch-pounds for low-torque work — small screws, electronics, and precision instruments — where a foot-pound reading would be too coarse. Keep foot-pounds for larger fasteners on engines, wheels, and structural joints.