the honest answer is that you can't.
not healthily at least,which you should be going for. The Insanity workouts, from my knowledge,can urn answer from 600-1000 calories per workout. 1000 if you're really pushing yourself.
make sure the amount you burn is not greater than 1000 calories over what you are consuming each day. If you are a adult woman, don't consume less than 1200 a day,and 1500 for adult man. If you are a teen,no less than 1500 for a girl and 1800 for a boy