🧲 Magnetic Moment Calculator
Calculate the magnetic moment of a current-carrying loop, and the torque it experiences in an external magnetic field.
1
A
2
cm²
3
4
T
What magnetic moment is
The magnetic moment describes the strength and orientation of a magnetic source, such as a current loop. This calculator finds the magnetic moment of a coil and the maximum torque it would feel in an external field.
The formula
Magnetic moment m = N × I × A, where N is the number of turns, I is the current through the loop, and A is the loop’s area. The maximum torque on the loop in a uniform external magnetic field B is τ = mB, which occurs when the loop’s magnetic moment is perpendicular to the field.
These are standard formulas from classical electromagnetism for an ideal planar current loop.
Last reviewed August 2026