Foot-Pound to Inch-Pound Torque Converter

Exactly 12 in-lb, because a foot has 12 inches. So 100 ft-lb = 1,200 in-lb and 25 ft-lb = 300 in-lb. This is the one conversion in the calculator that is exact (no rounding); every other relationship (N m, kg m, kg cm) involves the 1 ft-lb = 1.35582 N m factor and inherits a tiny amount of rounding error.

A newton-meter (N m) is the SI unit of torque: one newton of force applied at a one-meter lever arm. European and Japanese service manuals, bicycle component specs, and most modern car factory manuals quote torque in N m. To convert, multiply ft-lb by 1.35582 to get N m, or divide N m by 1.35582 to get ft-lb. The calculator does both directions and also shows kg m and kg cm, which still appear on older Japanese and European tool labels.

Passenger-vehicle engine torque varies widely by engine and drivetrain, so model-specific data is more useful than a generic range. Fastener torque also varies by vehicle, thread, material, lubrication, and tightening procedure. Use the service manual and a torque wrench whose calibrated range includes the specified value.

Click-type torque wrenches are usually rated plus or minus 4 percent of reading at mid-scale, and plus or minus 6 percent at the ends of the range. Beam-type wrenches sit around plus or minus 3 percent. Both lose accuracy in the bottom 20 percent of their rated range, so a 1/2-inch wrench rated 30 to 250 ft-lb should not be trusted below about 60 ft-lb. Calibrate yearly or every 5,000 cycles for spec-critical work, and always store click-type wrenches at their lowest setting to preserve the spring.

Use the unit printed in the service manual or component specification, then convert only if your calibrated tool uses another unit. Inch-pounds make small values easier to read, while foot-pounds are common for larger values. Confirm the exact specification rather than relying on a generic fastener range.