How many Calories burned during a 30 minute spin class?

200-500 calories depending on speed/resistance

Based on the average 130-pound person, you would burn about 210 calories in a 30-minute jog. However, it depends on height and weight, gender, and the amount of effort you put into it as well. It's...

i have been using a rate rate monitor for years, and at the weight of 150 lbs, my body burns between 500-650 calories/hr of spinning

It depends on what you are doing. Different exercises (or lack therof) will bunr very different amounts of calories in an hour and a half.

It all depends relative to body weight, resistance, speed (intensity), age, and where you are riding. For example, an 180 pound male, in average conditions, might burn somewhere close to 100 calories...