See, the nonce in Bitcoin is basically a number that miners keep changing to try to make the block comply with the network's rules. Think of the nonce range as searching for a specific combination on a lock, and that range goes from 0 to about 4 billion—pretty wide! When they run out of that range without finding anything valid, miners can change something else called the ExtraNonce, which expands the search possibilities. Ultimately, it's a process of trial and error. You don't calculate the nonce directly; you just keep trying until you find the number that works.