Having a hard time estimating how many calories I've burned.

Hey guys! I don't have the money for a heart rate monitor so I've been having trouble recording how many calories I burn a day.
I just started three days ago and I've been working out for 45-60 minutes a day. First I do 30-45 moderate latin dance moves and finish off with 10 minutes of moderate cardio. I've looked around on some sites and they all say I burn like 400 calories (I'm 250lbs, 5'10) but I find that unrealistic so I end up only putting in 200 calories.
I just wanted some input -- how much do you think I'm REALLY burning based of your experiences? Is 200 more reasonable than 400?