Here is the formula that Wahoo uses:
https://support.wahoofitness.com/hc/...o-Fitness-App-
So today, 75 miles, average heart rate 118. I weigh 145lbs and am 65 years old. All of that comes out to 31352 calories (actually Kcal for us nerds) which by my research comes out to about 20 beers. The new metric being BPR (Beers per Ride). I traded some of that for burgers and fries.