Pound-Feet to Newton Meters Converter (lb·ft to N·m)

US service manuals, auto-parts websites and the click wrenches in most American toolboxes use pound-feet, usually written ft-lb or lb-ft. Converting to newton meters is needed when a wrench or digital adapter reads only in N·m, when filling in metric documentation, or when comparing a US engine's torque with a European spec sheet.

The pound in this unit is a pound of force: one pound-force acting on a lever one foot long, at right angles to it. With the international foot and the standard pound-force, that comes to exactly 1.3558179483314004 newton meters, so the answers here are exact apart from display rounding.

How to use this tool

1. Type a value in the Pound-Foot box to see it in newton meters, or type in the Newton Meter box to convert the other way.
2. Press ⇄ to swap the two units, or Load example for a typical value.
3. Check the charts below for common values; for other units, open the Torque converter.

Formula

Newton Meter (N·m) = Pound-Foot (lbf·ft) × 1.35581794833

Pound-Foot (lbf·ft) = Newton Meter (N·m) × 0.737562149277

Both factors come from exact definitions: 1 newton meter = 0.737562149277 pound-feet and 1 pound-foot = 1.35581794833 newton meters (shown to 12 significant digits).

Example

Two conversions worked with the same factors the converter uses:

80 lbf·ft × 1.35581794833 ≈ 108.465 N·m

150 N·m × 0.737562149277 ≈ 110.634 lbf·ft

Pound-Foot to Newton Meter chart

Common values from pound-feet to newton meters, rounded to four decimal places.

Newton Meter to Pound-Foot chart

The reverse direction for values people often look up.

Torque figures in pound-feet

Quick mental estimate

Multiply by 4, then divide by 3: 90 lb·ft → 360 ÷ 3 = 120 N·m. That uses 1.333 per lb·ft, about 1.7% under the exact factor; add 2% at the end for a closer figure of about 122.

Use the converter or the charts when the exact figure matters.

The two units

Pound-Foot (lbf·ft): The pound-foot (lbf·ft, often written ft-lb) is one pound-force acting with a perpendicular lever arm of one international foot, exactly 1.3558179483314004 N·m. The pound here denotes force, not mass.

Newton Meter (N·m): The newton meter (N·m) is the SI unit of torque: one newton acting with a perpendicular lever arm of one meter. Torque has the same dimensions as energy, but is a different quantity and is expressed in N·m rather than joules.