Question about the "deficit"

So, is the deficit from the amount I'm burning during the day, or the amount of calories I'd need to maintain my weight?  I'm eating 1500 calories and burning 2500-2800ish each day...  So is that my deficit or is the amount that I'd need to maintain my deficit?

Subtract the number of calories you are consuming ~1500 from the amount you are burning ~2500-2800.  You have a calorie deficit of 1000-1300 calories.  For healthy weight loss the deficit should be somewhat less, about 500-1000.  If you are working out more on some days, eat a little bit more to keep the deficit approximately 1000 calories.