Solenoid (Electromagnet) Force Calculator

This calculator computes the force between a solenoid and another piece of ferromagnetic material separated by a gap of distance g.

F = (Fm)² μ0 A / (2 g²)

F = (N*I)² μ₀ A / (2 g²),

Where:

• μ0 = 4π10-7
• F is the force in Newtons
• N is the number of turns
• I is the current in Amps
• A is the area in length units squared
• g is the length of the gap between the solenoid and a piece of metal.

Note, any units can be used for A and g so long as they are consistent. For example, in² and in, or m² and m, respectively.