Is there a way to calculate the magnetic field strength, B, of a magnet (permanent magnet, not an electromagnet) at a certain distance? I assume it follows the inverse square law, but other than that, I do not know what to do. Tools I have available: permanent magnet ammeter/voltmeter wire batteries spring scale ruler I am aware of the equations: F=8.99*109q1q2/r2, F=qVB(sinθ), and F=BIL(sinθ), but I do not know how I would use those to calculate the field strength with just the tools listed above. Also, if you were to cut a magnet in half, would that half the strength of the magnetic field? Does every type of permanent magnet material have some kind of Tesla per meter2 per kilogram constant?