Pound-foot (torque)

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Unit system British Gravitational System, English Engineering Units
Unit of Torque
Symbol lbf∙ft 
Unit conversions
1 lbf∙ft in ... ... is equal to ...
   SI units    1.355818 N⋅m
   Gravitational metric system    0.1382550 kgf⋅m

A pound-foot (lbf⋅ft or lb⋅ft) is a unit of torque (a pseudovector). One pound-foot is the torque created by one pound force acting at a perpendicular distance of one foot from a pivot point. Conversely one pound-foot is the moment about an axis that applies one pound-force at a radius of one foot.

One pound-foot is approximately 1.355818 newton meters.

The name "pound-foot", intended to minimize confusion with the foot-pound as a unit of work, was apparently first proposed by British physicist Arthur Mason Worthington.[1] However, the torque unit is often still referred to as the foot-pound (ft⋅lbf).[2]


  1. ^ Arthur Mason Worthington (1900). Dynamics of rotation : an elementary introduction to rigid dynamics (3rd ed.). Longmans, Green, and Co. p. 9. 
  2. ^ Erjavec, Jack. Manual Transmissions & Transaxles: Classroom manual. p. 38. ISBN 978-1-4354-3933-7.