Repulsion / attraction force between magnets

[sebitab]

Hi, I am needing some guidance to find a way to calculate the repulsion or attraction force between (magnet/magnet) or (magnet/coil) in kg force.

I know there is not a fast or easy answer to this but you will help me a lot if you can help me finding the way to calculate it.

thanks for your help in advance

regards
sebastian

 

[cragar]

What about using 2 solenoids with current I , and using amperes law to find the B field.
Or what about doing it experimentally.