A water change should do the trick
Goldfish tend to get torn fins when the nitrates are too high (or when the water quality is generally bad), so take out a good 60% of the water and vacuum the gravel thoroughly.

How big is your tank? How much does your filter turn per hour and how many goldfish do you have in total in this one aquarium?

They'll heal for sure. Only problem (don't start imagining that it's there now), would be if the fins would rather look "cut off" and torn at the same time, you know, all whitish on the edges etc. This would be a sign of fin rot.
And you didn't answer how powerful your filter is Your tank is slightly crowded, so if your filter is too small as well (if possible, nothing smaller than 290 gph), it's not powerful or big enough to deal with the waste of the fish.