One number changes everything: the calories your weight balances at. Everything in nutrition - every cut, every build - is measured from here.
Confusing a smartwatch's burn estimate with reality. Forgetting NEAT quietly collapses when dieting. Testing maintenance for three days and calling it proven - it needs two full weeks of averages.
Maintenance is found, not calculated. The formula gives the starting line; then we eat there, weigh daily, average weekly, and let your own data confirm or correct it. That two-week test is worth more than any calculator - this one just makes sure you start close.
Treat this as an evidence-based starting point, not a prescription. No formula can see the things that genuinely shift your real requirements - sleep quality, stress, hormones (thyroid, cortisol, the menstrual cycle), medication, recovery, how much you move outside training, how accurately you track, and the way your metabolism adapts as your body changes. Two people with identical stats can respond very differently. That gap between the estimate and your reality is exactly what coaching closes - your day-to-day data, reviewed weekly by a human, with targets adjusted from how your body is actually responding rather than what a formula predicted. That’s the HALLMARK standard →