How many calories should I eat to lose fat?

Most people lose fat well at roughly 10 to 20 percent below their maintenance calories. Estimate maintenance from your bodyweight and activity level, subtract a modest amount, then adjust based on two to four weeks of real-world weight and measurement trends rather than a single day.

A rough starting estimate

A common shortcut is 30 to 35 calories per kilogram of bodyweight for maintenance in a moderately active person, adjusted up for high activity and down for low. For an 80 kg person that gives roughly 2,400 to 2,800 calories, so a fat-loss intake might start somewhere around 2,100 to 2,400. Treat this as a hypothesis to test, not a prescription.

How to test and adjust

• Hold the intake steady for two to three weeks.
• Weigh yourself several times a week and compare weekly averages.
• If the average has not moved, reduce by around 150 to 250 calories a day.
• If loss is faster than about 1 percent of bodyweight per week, add calories back.

Structuring the intake

Set protein first, at roughly 1.6 to 2.2 g per kg, because it protects muscle and helps with fullness. Keep enough fat for hormonal health, commonly around 0.6 to 1 g per kg. Fill the remainder with carbohydrate to fuel training. Meals built around protein, vegetables, and fibre tend to be far more filling for the same calories.

Why calculators disagree

They use different formulas and none of them can see your daily activity, which varies by hundreds of calories between people of the same size. This is why the adjustment phase matters more than the starting number.

A floor worth respecting

Very low intakes make it hard to meet protein and micronutrient needs, harm training quality, and are difficult to sustain. If your calculated deficit lands somewhere very low, it is usually better to increase activity than to cut further. Anyone with a medical condition, who is pregnant or breastfeeding, or who has a history of disordered eating should set intake with a doctor or registered dietitian rather than from a general guideline.