Your question is actually huge Marie. I can't answer it simply but I'll try .. all movement burns energy/calories. Using the CV9 can range from gentle therapy movement through to hard exercise positions and with different settings/speeds/force, so the calorie burn varies.. Much more important though is that is you increase your fitness and muscle strength a little even, you also increase your metabolic rate..then you burn calories at a higher rate all day and all night, even sleeping.. contrast this to running on a treadmill where you only really burn calories while you are using the treadmill, then 5 minutes later it's all stopped.. But is this the right machine for you or the right way to meet your exercise needs and goals? you haven't given enough information for anyone to answer.. if its all about calories I am going to presume you want fat-loss and overall fitness, and yes the CV 9 could be a great place to start.. Moderate your eating also of course......... I hate the How many calories question (sorry not personal). It's not the right question to start with. it all depends on your needs and goals.. Please contact a Cardiotech agent (I am not one) and if you don't get the answers you need, ask them for the email of the CEO or see if you can locate my email and I will guide you. Cheers