Diamondback Fitness uses a calorie calculation recommended by the ACSM (American College of Sports Medicine) to estimate the rate at which you are burning calories during a workout. It is based on the body weight you enter into the machine and the amount of power generated by the machine when you pedal. We can estimate this power by knowing the pedal speed and resistance level (and on some machines, the incline level) you are using. The calculation may be a bit more conservative than that of some competitors, but it also tends to be more accurate.
Since the calculation takes body weight into consideration, remember to enter your body weight into the machine at the beginning of the workout to get an accurate calorie estimate, otherwise, it will assume a default weight of 155 lbs.