Incorrect calories burned

[Mich24]

The last two days my calories burned is half what it normally is for past several months. And today I walked more than usual. Is there an error? It says I’ve only burned 900 calories when my average is well over 2000. This is on both the Fitbit and the phone app. 

Moderator Edit: Clarified subject

[JohnnyRow]

Check your weight didn't get changed to something way too small.

[CindyMFitbit]

It's great to see you around @JohnnyRow. Welcome to the Community Forums @Mich24. 

Thanks for the details shared in your post. Note that 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. 

Your BMR is based on the physical data you entered in to your Fitbit account (height, weight, sex, and age) and accounts for at least half the calories you burn in a day, so as @JohnnyRow suggested, let's review your personal settings just to make sure that they are correct. 

Additionally, I suggest restarting your Fitbit device, to refresh the settings on it. For instructions see, How do I restart my Fitbit device?

See you round.