Find magnetic field from temporary magnet

[SirHall]

What I've not been able to find after literally spending several hours researching is if you can find the formula to find the magnetic field strength from a temporary magnet. Or, to be put in better terms, what would be the force between two objects if one is a magnet and the other is something like a piece of iron? I've found $F=\frac{KBH}{d^2}$
Where:
F = Magnetic Force
K = Magnetic Permeability
B = Magnetic Field
H = Second Magnetic Field

What I haven't been able to find however is how to find the magnetic field of 'H', or the magnetic field of the 'iron'.
Thanks for answers

 

[mfb]

It is complicated. To get some rough approximation, you can assume that the second magnet will produce a magnetic field as strong as the field at its place without the magnet.

 

[SirHall]

It is complicated. To get some rough approximation, you can assume that the second magnet will produce a magnetic field as strong as the field at its place without the magnet.

Thanks, and if it's not too much to ask, would there be a way to approximate or find that?

 

[mfb]

Approximate what, the field from the magnet at that point? If the distance is large enough, you can approximate your magnet as a dipole and use the formula for dipoles.