Calorie Expenditure HIT

Hey All,
I know you're probably sick of this question, but what is a good estimate of calories burned while doing HIT routines? All the sites I have reviewed say around 400 and hour, but I really think that's kinda low. I do an approximate 30 minute drill with a minute break every 12 minutes, comparitively I do 30 minutes on the eliptical at decent resistance for a sub 10 min / mile pace. The eliptical says I burn around 310 calories, which I expect is slightly higher than what I actually burn. If I use the 400 calories per hour for HIT, 30 minutes should be around 200, but I know I am expending way, way more effort with the HIT than the eliptical. I'd like to get a good feel for what the true expenditure should be so I can kinda track things better. Just for reference, I'm male, 5'4", 48 and 191 with more muscle mass than fat. Thanks in advance for any information.