Recumbent Bike (Stationary) Calories Burned help

dhaemon

This bike seems to be an enigma. Seems like there is no consensus on how many calories you burn on this machine.
What I do know is that it gave me that most satisfying workout as I sweated BUCKETS for 30 minutes, with automatic alternating resistance levels. I could barely talk as I keep a pace of 19 KPH. I ended up with a distance of 9.663 kilometers or 6 miles for you American folk.

Special note:
When I use Endomondo and state a vigorous effort, I burned over 1200 calories in 30 mins. With the amount of sweat that poured out of my body, relative to a 30 min walk, where I would burn 650 calories with barely any sweat. I'm thinking that it's true.

Any help would be appreciated in figuring out my calorie loss

Age: 37
Sex: Male
Weight: 436 lbs