How big a deficit you need, how long it will take, and whether the pace you have in mind is realistic.
A kilogram of body fat stores roughly 7,700 kcal, so a 500 kcal daily deficit predicts about half a kilo a week. That's the standard maths, and it's the maths this page does.
It is also the reason most people conclude their body is broken. Real weight loss isn't linear: water shifts, glycogen, sodium and hormonal cycles move the scale by a kilo or more in either direction, and adaptive changes mean your maintenance drifts downward as you lose. A week where the scale doesn't move is normal and usually means nothing.
Roughly 0.5–1% of body weight per week is the range most people can hold without losing muscle or willpower. Faster tends to cost you both, and the regain rate is worse. If the number this page gives you looks brutal, that's information — pick a slower pace rather than a shorter timeline.
Not the target. Whether you can tell, six weeks in, that the trend is real and not noise — and whether anything corrects the plan when it isn't.
Chiron holds your meals, training and weight together, so it can tell a stall from a bad week — and say what to change.
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Chiron is a wellness coach, not a medical provider. These calculators use population-level formulas and give you an estimate, not a diagnosis or a prescription. Talk to a doctor before making significant changes if you have a medical condition, are pregnant, or are managing an eating disorder.