Calories burned are low...

[SunsetRunner]

I know this has been talked about before but no real solution was given. My calories that are burned seem really low for the intensity of my workouts. I. E. during a weights based workout I spent 29 minutes in the cardio mode, 13 in fat burn, 14 in custom and 3 in peak with an average of 134bpm but my calories are only 260... this is for a 45 minute workout. This seems to be across the baord whether it be a cardio based workout or strength based. I am 5’2” and 115pds. I don’t care how much I burn but I use that as a measurement for how intense my workout is and if that is off, is the heart rate monitor off too? This is my first fitbit and I am considering sending it back...

[SilviaFitbit]

@SunsetRunner Welcome to the Community. Sorry for the delayed reply. 

Thanks for the detailed information shared. Your calories burned are tracked using your heart rate, please try these tips to improve your heart rate data. 

Fitbit devices combine your basal metabolic rate (BMR)—the rate at which you burn calories at rest to maintain vital body functions (including breathing, blood circulation, and heartbeat)—and your activity data to estimate your calories burned. If your device tracks heart rate, your heart-rate data is also included, especially to estimate calories burned during exercise. The number you see on your Fitbit device is your total calories burned for the day.

Learn more about it by checking this article: How does my Fitbit device calculate my daily activity? 

I'll be around if you have any additional questions.