How to calculate your calories for fat loss: a simple 4-step method

Fat loss comes down to one idea: eat a little less than your body burns, for long enough, without losing your muscle. The rest is execution detail. Here is a four-step method, with numbers you can recalculate yourself using our calorie and macro calculator.

1. Find your maintenance calories

Your maintenance calories (total daily energy expenditure, or TDEE) are the ones that keep your weight stable. They are calculated in two steps: basal metabolic rate (what your body burns at rest), then an activity factor.

The Mifflin-St Jeor equation is the most widely used: for men, 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5; for women, the same calculation with −161 at the end. You then multiply by 1.2 (sedentary) up to 1.9 (physical job and hard training). Example: a 30-year-old man, 75 kg, 175 cm, active (×1.55), has a BMR of about 1,700 kcal and maintenance close to 2,630 kcal.

This is only an estimate, with a margin of roughly ±10%. Step 4 exists precisely to correct it with your own data.

2. Pick a reasonable deficit

The bigger the deficit, the faster the loss, but the more hunger, fatigue and muscle loss you get. A deficit of 10 to 20% of maintenance, which is 300 to 500 kcal for most people, is a good compromise: it matches losing 0.5 to 1% of bodyweight per week.

• Little to lose (under 5 kg): aim for about a 10% deficit to protect your muscle.
• More to lose: 15 to 20% is sustainable for 8 to 12 weeks.
• Beyond 25%, muscle loss and binges become common, with no lasting gain in speed.

For our example, a 15% deficit gives about 2,240 kcal a day, a little under 400 kcal below maintenance.

3. Set protein, fat and carbs

Protein comes first: it protects muscle mass and keeps you full. Between 1.6 and 2.2 g per kilo of bodyweight suits most people who train, with the upper end during a deficit. For 75 kg that is 120 to 165 g a day.

Then roughly 25% of calories from fat (essential for hormones and absorbing some vitamins), and the rest from carbs, which fuel your sessions. You do not need to hit the numbers to the gram: a ±10% range is enough.

4. Adjust with the scale, not with theory

Weigh yourself 3 to 4 mornings a week under the same conditions and look at the weekly average, not a single number: water, salt and digestion move your weight by 1 to 2 kg from one day to the next.

• After 2 to 3 weeks, if the average drops 0.5 to 1% a week, change nothing.
• If it does not move, remove 100 to 150 kcal a day or add 1,000 daily steps.
• If it drops more than 1.2% a week, add back 100 to 150 kcal: you are going too fast.

Add a waist measurement every two weeks: it sometimes moves while the scale stalls, especially if you strength train.

The mistakes that cause most failures

• Underestimating what you eat: drinks, cooking oil, snacks and weekend meals often add up to 200 to 500 uncounted kcal.
• A deficit that is too aggressive, held for three weeks then dropped. A small deficit held for twelve weeks beats a big one held for three.
• Weighing yourself daily without averaging, and concluding that “nothing works”.
• Ignoring steps and sleep: sleeping under 6 hours increases hunger and sugar cravings.

What about training?

Nutrition makes you lose weight; strength training makes that weight fat rather than muscle. Three strength sessions a week plus walking are enough. If you want a ready-made framework, our Weight loss program: 12 weeks follows exactly that logic, and Home weight loss program: 8 weeks works with no equipment.

The information in this article is general and does not replace advice from a doctor or dietitian, especially during pregnancy, with a medical condition, on medication or with a history of eating disorders.