Two different kinds of number
An online TDEE calculator answers: what does someone with your stats burn, on average? It's a population formula — the same inputs always produce the same output, whether or not it fits you.
Your expenditure in Gravl Macros starts from a formula too, but then measures you: your logged intake against your actual weight trend, week after week. It stops being an average and becomes an observation.
So which is right?
For you? The observed one — assuming your logging is reasonably consistent. Metabolisms genuinely vary around the population average, activity multipliers are self-reported guesses, and calculators can't see any of it. A gap of a few hundred kilocalories between your estimate and a calculator isn't an error; it's information about you specifically.
When to trust it less
Early on (Initial or Refining confidence) the estimate is still mostly formula — expect calculator-like numbers until your data accumulates. And if logging has been thin, the estimate pauses rather than drifting; a stale number deserves the same skepticism as any formula.
The practical takeaway
Stop cross-checking against calculators once you're at Refined — at that point the calculator is the less-informed opinion. Feed the estimate good data and let it be what a formula can't: yours.