i have a heart rate monitor that will give me my average HR at the end of my ride but it doesnt give calories...is there a general formula where i could use my time, distance and HR data to get my calories burned?

40 calories per mile is a good rule of thumb. A little more if you're big, a little less if you're small. A little more if you're climbing a lot, a little less if on the flats. A little more if you sit upright or the wind is blowing hard, a little less if you're in a paceline or you're down on aero bars.

Most rides for most folks will come in between 35 and 45 calories per mile.

Looking at some of my polar data (which I think is OK but not great for calorie information - you really need a power meter to get good numbers), I see numbers in the 35-50 range (though 50 is really hard to get). Though I did have one outlier of 15 calories per mile on a really, really, easy ride with my family.

I read this in a post you made a long time ago. "40 calories per mile" has been one of the most useful facts I've ever learned on Bikeforums. I use it every day to get a rough idea of where I'm at with energy balance. Combined with weekly body weight, I've got a good handle on my weight problem for the first time in my life.

Thanks a million, SSP!!

At what speeds are you talking about for the calories burned?

I was just looking at my data for a long ride Sat. I'm at 167 pounds. 200 miles pretty flat, average speed 20mph, calories burned 6,500, equals 32.3 calories per mile. The only time I have gotten up to 40 calories per hour is on hard rides such as an 82 mile ride with 6K feet of climbing - 16.45mph average. On a 40 mile ride I did last week I hit 42.5 cals per mile - that was at an average speed of 17.8mph including a 30 minute interval at 22mph. Obviously body weight affects it as does intensity (hills) not just speed. Most of my recovery rides are at 30 cals per hour.

Speed doesn't mean anything in calorie loss. In fact, it's completely unpredictable. Here's the chart of my calories/mile and calories:speed over the last 9 months (using a powermeter)

Calories/mile is right around 40. I added a 7 day avg trendline to highlight the tops of the bars.

Not quite sure what your point is...but, since most of us are:

a) limited in terms of exercise time, and

b) we burn more calories per hour going faster

Going faster is generally a better strategy for weight loss than "long slow distance".

I was responding to the question from Fred61 about speeds vs calorie loss. I think the chart is obvious that speed compare to calorie loss is of no use.

The point is, if you want the best calorie loss, go harder, which is not necessarily faster.