Free · Physics models
Current Loop and Solenoid Magnetic Moment
Estimate the magnetic moment magnitude and sign from current, loop geometry and winding count.
- Formula & worked example
- Private in your browser
- No signup
Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
Private by default
Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.
Formula and method
A 1 m radius circular loop carrying 2 A has area π m² and magnetic moment 2π A·m².
mloop = I A; mcoil = N I A; Acircle = πr².
Worked example
Enter these known values and leave the other values blank.
- Current
- 2 A
- Radius of the loop
- 1 m
- Length of the loop
- 6.283 m
- Loop area
- 3.1416 m²
- Magnetic dipole moment
- 6.283 A⋅m²
Assumptions and limitations
- Ideal circular loop or coaxial turns with uniform current. The moment direction follows the chosen current orientation.
- Signed current produces signed moment; the geometry is positive and solenoid turns are positive integers.
- The area and circumference relations presume a circle, rather than an arbitrary wire shape.
- Enter known quantities and clear the unknown to use available inverse branches. Locks retain supplied values. Consistency messages cover fully visible equations; identities with hidden dependencies may require a manual consistency check. Preset values are illustrative approximations, and unit selectors preserve the underlying quantity.
Common questions
How do I solve for a different quantity?
Clear that quantity and supply enough independent known values. Some outputs are one-way or tied to a selected preset, so they cannot determine every input.
References
The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.