How Many Calories Should I Eat to Lose Weight?

The arithmetic is simple and the execution is not. Eat below what you burn and you lose weight — but the number you are subtracting from moves as you go, and the scale lies for weeks at a time.

Start from TDEE

Total Daily Energy Expenditure is everything you burn in a day: basal metabolism, movement, exercise, and digestion. Estimate BMR with Mifflin-St Jeor, then multiply by an activity factor between 1.2 (desk job, no training) and 1.725 (six sessions a week).

Your intake target is TDEE minus a deficit.

Choosing the deficit

The classic guideline says 3,500 kcal equals about 0.45 kg (1 lb) of fat, so a 500 kcal daily deficit produces roughly a pound a week. It is a reasonable planning tool for the first few months and it drifts afterwards — the constant assumes fixed tissue composition and a metabolism that does not respond.

A useful alternative to fixed numbers: target 0.5-1.0% of body weight per week. Heavier people can safely run larger absolute deficits; someone near their goal weight should not.

Worked example

A 90 kg man, 180 cm, 38 years old, training three times a week:

1. BMR = 10(90) + 6.25(180) − 5(38) + 5 = 900 + 1,125 − 190 + 5 = 1,840 kcal
2. TDEE = 1,840 × 1.55 = 2,852 kcal
3. Deficit of 600 kcal → target 2,250 kcal/day
4. Expected loss ≈ 0.54 kg/week, about 0.6% of body weight — comfortably in range

After losing 8 kg, recalculate. His BMR drops to roughly 1,760 and TDEE to about 2,730, so the same 2,250 kcal now represents a 480 kcal deficit rather than 600. This is why progress slows even when nothing about your eating changed.

Set a floor

Do not go below your BMR for extended periods without medical supervision, and as a practical floor, most guidance puts the minimum at around 1,500 kcal for men and 1,200 for women. Below that it becomes difficult to hit protein and micronutrient targets, adherence collapses, and a larger share of the loss comes from lean tissue.

Protein protects against that: 1.6-2.2 g per kg of body weight per day, plus resistance training, keeps most of the loss as fat.

Why the scale misleads

• Water shifts. The first week often shows 1-3 kg of loss that is mostly glycogen and its bound water. It is not fat and it does not repeat.
• Plateaus. Fat loss continues while water retention masks it, then the scale drops several hundred grams overnight. Judge by weekly averages, not daily readings.
• Adaptive thermogenesis. Sustained dieting reduces non-exercise movement and slightly lowers metabolic rate beyond what the weight change predicts — typically 5-10%.

Recalculate your target every 4-5 kg lost, or every six to eight weeks.

FAQ

How many calories should I eat to lose 1 kg per week? Roughly a 1,100 kcal daily deficit, which is aggressive for most people. A 0.5 kg per week target is more realistic and better preserves muscle.

Why am I not losing weight in a calorie deficit? Usually intake is underestimated (untracked oils, drinks, and portions), or the deficit has shrunk as your weight fell. Water retention can also hide two or three weeks of real progress.

Is eating 1,200 calories a day safe? It is a common floor for smaller women but is too low for most men and anyone training seriously. Prefer a smaller deficit sustained longer.

Find your baseline with the TDEE Calculator, set the target with the Calorie Deficit Calculator, and split the intake using the Macro Calculator. Background on the two numbers: BMR vs TDEE.

*General information only, not medical or dietary advice. Consult a clinician or registered dietitian before starting a weight-loss plan.*

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*Get your number in thirty seconds: use the Calorie Deficit Calculator.*