Maintenance calories is an ever-evolving target dictated by numerous variables. Yes, you can predict your potential maintenance calories based off formulas.
However, it’s important to note that different formulas will produce slightly varied projections. Theoretical projections are nice to know but it’s important to base your decisions off the reality of the situation and your physical progress.
Additionally, as your circumstances change, your caloric needs can move greatly. This is simply due to an alteration in energy demands as your activity and conditions evolve. Here you can see numerous examples of this occurring. A change in job from sedentary to standing changes your needs, as can the acquisition of a new partner or pet. Thus, close assessment, flexibility and experimentation is required to assess your true calorie needs at each point in time.
Finally, while using an activity tracker such (Apple watch, FitBit etc.) to estimate calorie needs sounds like a good idea. The reality is this is generally a suboptimal choice as the accuracy of these trackers is typically poor. For instance, with under and over feeding, our energy output can shift greatly according to the conditions. This is because our body can become more efficient or inefficient in terms of energy use according to the situation as a counter measure to the conditions. An activity tracker won’t be able to account for this.
The take home message is that your calorie consumption needs to be nimble and move as the conditions evolve. Additionally, use activity trackers and calorie formulas as purely a guide and not gospel in regards to your energy needs.