Manual powered treadmill. Calories??

QueenKatherineElizabeth

Just got a manual powered treadmill. Aka a treadmill without the need for electricity and I make it go by walking on it. There is tension on it to make it work. So it feels like I have to work twice as hard just to walk on it to keep it going. Plus the fact that it has a slight incline to the machine as well. It's called a Nordic track walk fit. It's got a screen on it but it barely works to see the numbers and it quits counting after a minute and a half. Would love to figure the calories I burn on it. Please help. Thank you.