I tend to track my bike rides using the app endomondo on my android phone. When I get back I put in the workout using the mileage tracker by putting in the duration and the number of miles. I have found that often there is a huge difference between the list of calories burned between the two.
An example: today was a 20mi bike ride in 143min. According to endomond calories burned was 1458 while spark said 812, which is almost half. If they were close I wouldn't worry about it, but since there is such a big difference I was wondering on which one would be more accurate.
Unfortunately a heart rate monitor won't fit into the budget for a while
| current weight: 191.4