How many cups of frozen, thawed strawberries do I need to equal 3 cups fresh strawberries?

The recipe I want to use to make strawberry jam calls for 3 cups "prepared" strawberries, or about 3 pints fully ripe strawberries. I have a ton of frozen strawberries in the freezer and the produce where I live isn't all that great so I'd like to not waste money on fresh strawberries when half of them are going to be going bad anyway. But I know the volume changes when you freeze and defrost them, since the juices run out. Should I just measure 3 cups of frozen strawberries and then defrost that, or what? Thanks for any help. =)