How much caffeine would one need to burn fat on a daily basis?

In accordance with a workout routine and good diet/lifestyle.

I weighed 260, and was 12% bodyfat at 5'11.

Unfortunately, I got injured and Im back down to 230 and round 15%bf.... got some caffeine pills left over from a lil while back. Thinking about using them to burn some fat but Im not sure exactly how much to use....

And no roids ever... As Im only 21 and too young