How many calories should I eat to lose fat?
Fat loss comes down to eating fewer calories than you burn — a calorie deficit. Your maintenance figure is roughly what you burn in a day; eat consistently below it and your body makes up the difference from stored body fat.
The size of that deficit is a trade-off. Bigger means faster, but it's harder to stick to and hits training performance sooner. A deficit you can hold for months beats an extreme one you quit in week two.