How this calculator works
The newton metre and the joule are both one newton multiplied by one metre, so their magnitudes are identical. Engineers still distinguish torque from energy because the directions matter: torque is a vector moment about an axis, while energy is a scalar transfer. One foot-pound of energy and one pound-force foot of torque also have the same magnitude in the SI system, which is why a single conversion table serves both. The calculator therefore uses the same numeric base for every unit.
Formula
value in N·m = entered value x F(torque unit), or value in J = entered value x F(energy unit). F(N·m) is 1, F(N·cm) 0.01, F(lbf·ft) 1.3558179483, F(lbf·in) 0.1129848290, F(kgf·m) 9.80665 and F(dyn·cm) 10^-7. The joule row uses the same factors with J in place of N·m. 1 cal = 4.184 J and 1 kWh = 3,600,000 J.
Worked example
10 N·m is 10 J, 0.01 kJ, 0.00239006 kcal, 7.37562 ft·lb and 88.5075 lbf·in. 1 ft·lb is 1.35582 N·m and 1.35582 J. 1 kWh is 3,600,000 N·m.
Advertisement
Frequently asked questions
Is a newton metre exactly a joule?
Numerically yes: both are one newton times one metre. In engineering they are kept as separate named quantities because torque and energy behave differently in equations, and mixing them freely hides sign and vector errors.
Why show foot-pounds as both energy and torque?
The unit name is overloaded in ordinary use. A foot-pound of work and a pound-force foot of torque have the same magnitude, but one is a scalar energy and the other is a moment about an axis.
Does this account for a lever arm?
No. It converts a torque you already have. To find a torque from a force and a lever arm, multiply the perpendicular force by the distance first.