Which calorie burn is right? Strava vs Endomondo

[strawberry_]

I went on a bike ride today to test 2 apps that I have connected to Fitbit. 

First I used Endomondo to go one way. I biked 5.11mi in 27min with an avg heart rate of 130bpm. Endomondo set my calorie burn at 319 calories in its app with no HR data, and that calorie burn got synced with my Fitbit.

On my way back I used Strava. I biked 5.79mi in 28min with an avg heart rate of 138bpm. Strava shows a calorie burn of 160 in its app but it synced with the Fitbit as 234 calories. (suggesting the number was adjusted for HR)

Which value is closer to being correct? Endomondo or Strava? I am 5'1, 173 pounds. I find it confusing how I can get a lower calorie number traveling a longer distance with a higher heart rate. 

"For weight loss" I can always go for the lower number, obviously. But I'm not interested in stats for weight loss. I'm interested in which number is closer to being accurate.

Endomondo vs Strava screenshots:

[slysam]

All calorie burn numbers are guesstimates. Keep that in mind. One source of difference can be different formulas for your base calorie burn (BMR/RMR which represent calories someone with your stats would burn without activity). I know you are asking about exercise, but this is often built into the formula used by various app, activity trackers, gym cardio machines and heart rate monitors and can make a difference. I would trust the method that uses the most data about you. You want to make sure your height, weight, age and gender are correct. My guess is probably Stava since it would have your stats, the activity (that can be important), distance and heart rate data. But I haven't used Stava. Some apps report heart rate for training purposes, but don't use it in the calorie burn estimates. 

[strawberry_]

I used a Polar chest strap to track a previous bike ride a while ago. The avg HR is pretty close to 138BPM, so halving this exercise to 30min interval calculates to ~240 calories burned (BMR cals included in this value), which is more in line with Strava's value. 

Honestly, I prefer using the Endo app due to its easier User Interface. However, I can't wrap my head around why the calorie burn is so high. The comparison is nice to have. 

[Dominique]

Try to compare the calorie burn to what the Compendium of Physical Activity would give you, based on your BMR per minute (to determine your BMR, you can use this online calculator). According to the compendium, biking at 10-12 mph is 6.8 METs. If your BMR were 1500 (1.04 cal. per min.), you would burn 6.8 x 1.04 x 27 = 191 calories in 27 minutes.