Veritas-in-Caritate

I'm trying to understand Archimedes principle. I understand that the buoyancy force on a submersed object is equal to the amount of water displaced by the object. But how do you measure these things? How is it that a force can equal a displaced object? How do you measure the buoyancy force and then compare it to an amount of liquid that was displaced? Wouldn't these be two different types of measurements? How then can they equal each other?