Technically, it’s difficult to determine one’s DREE (Daily Requirement of Energy Expenditure). Plus, it’s going to differ day to day due to different levels of activity and intensity as noted above by @RobC. Basing DREE on something like Chronometer is useless, since Chronometer does a calculation based on overall averages of many people under many different situations that probably do not apply to you. So there’s no point obsessing about a couple hundred calories plus/minus on Chronometer.
That said, it’s fairly easy to determine your approximate DREE by trial and error. You need to track your calorie intake and weigh in weekly, and it will take a few weeks to get it close enough to be useful.
What you need to do is eat to the point where you start to lose weight consistently. It doesn’t matter how much, just so you’re losing. If you are in ketosis, you will probably not feel hungry. That’s why you have to use the scale to determine that you are in a losing state. Eat only that amount for a couple of weeks so sustain the loss.
Then over the course of a week or so, eat a hundred calories more. Repeat until the weight loss stops. That point is your approximate DREE.
I say approximate because whatever that calorie number, it is simply more or less the middle of a plus/minus range of a couple hundred calories or so up/down. If your level and/or intensity of activity changes, so will your DREE.
In my own case, I initially determined that 2500 calories per day was my DREE. If I ate a couple hundred calories less for several days in a row, I would start to lose weight. If I ate a couple hundred calories more for several days, I’d start to gain. That worked for a year to maintain my weight at 150 pounds.
A year later I got a full time job at Walmart. Within a couple of weeks I started losing weight. So I upped my daily calories to 2700 to stabilize again at 145 pounds. That’s where I’m at now, a year and a half later.
You can also track your approximate body fat loss with a caliper and tape measure. The scale is not very useful for that.
Hope this helps. 