Treadmill/calories burned

nik1970

Hi, I was wandering if anyone had any advice on how to figure calories on treadmill without using heart monitor. I hope to get a heart monitor soon. How accurate are the treadmills on figuring calories? I read somewhere that they estimate it based on a person that weighs around 154 pounds. I weigh 150 now and i walk at a pace of 3.5 to 4.0 MPH and an incline of 7 to 10. My heart rate according to the treadmill is getting up as high as 159 but ranges between 120 to 145. For instance today i walked 30 minutes and it said i burned 300 calories, is this a fair estimate or too high? I am sweating quite alot! Appreciate any advice ...Thanks