The starting point
When you set up your plan, Gravl Macros estimates your daily energy expenditure from your body data: your lean mass drives the baseline (which is why body fat percentage is asked for), and your daily activity, exercise frequency, and cardio experience scale it up. During setup you can confirm that first number, adjust it manually if you know better, or mark it as "not sure" — in which case a slightly conservative estimate is used.
That first number is just the seed. The interesting part starts once you log.
How it adapts
Energy balance leaves a trail: if you eat a known amount and your weight trend moves a known amount, the difference tells you what your body actually burned. The algorithm applies exactly that logic, continuously — comparing your logged intake over the recent weeks against how your trend weight moved, and nudging the estimate toward what the evidence shows.
Because it learns from your data, it captures what generic calculators can't: your real activity, your metabolism, your logging habits. Early on it moves faster to find the right level; as your history builds, it becomes deliberately more stable so one unusual week doesn't swing your targets.
What it needs from you
Two habits keep the estimate alive: logging your food and weighing in. Roughly, the algorithm wants most of your days logged and at least one weigh-in each week — when the data gets too thin, it pauses rather than guessing (see Why Your Expenditure Is Paused).
What it is — and isn't
The number on your Expenditure screen is an estimate with a confidence range, not a measurement. Its shaded band shows how much uncertainty the recent data leaves. Expect it to move by small amounts as it learns; that movement is the feature.