OTB Fitness Band vs Versa calorie count

[SunsetRunner]

Hey guys, 

I've done a lot of research and im finding that everyone is having the opposite effect I am and I'm not sure what to do. 

On average, when I go to Orange Theory Fitness class their HR monitor tells me I burned anywhere from 400-600 calories a class. My Fitbit Versa says I burn on average 1400-1500 calories a class and over 4000 a day. 

I base my performance and intake based on OTB because I don't want to overeat because my Versa says I burned 3x the amount of calories. 

Which one is correct?

Some background,

Current Weight: 381.1

Moderator edit: subject for clarity

[LiliyaFitbit]

Welcome to the Fitbit Community @SunsetRunner. I am sorry for the delayed response.

I appreciate your participation in the Forums and sharing your concern regarding the number of calories your Fitbit Versa is counting for your Orange Theory Fitness class. Thank you for your efforts to resolve the issue and providing the additional details. The calorie burn estimate that Fitbit provides takes into account your BMR, the activity recorded by your tracker, and any activities you log manually. Your basal metabolic rate (BMR) is the rate at which you burn calories at rest just to maintain vital body functions like breathing, heartbeat, and brain activity. For more information, please see this help article: How does Fitbit estimate how many calories I've burned?

Since you see a big difference, I recommend confirming that your personal details are correct (For more information, see How do I manage my Fitbit profile?). I also suggest restarting your device by following the steps from this help article: How do I restart my Fitbit device?

Let me know how it goes!