How Many Calories Should You Eat? BMR, TDEE Explained

"Eat less, move more" is technically true but not very useful. The actual number of calories your body needs depends on your age, sex, size, and how active you are — and once you know that number, weight loss, maintenance and muscle gain all become a matter of simple math.

BMR: What Your Body Burns at Rest

Your Basal Metabolic Rate (BMR) is the energy your body needs just to stay alive — breathing, circulating blood, maintaining body temperature — assuming you did nothing but rest all day. The most widely used formula for estimating it is the Mifflin-St Jeor equation, which uses your age, sex, height and weight. It's more accurate for most people than older formulas like Harris-Benedict.

TDEE: Adding Your Activity Level

Your BMR is just the starting point. Multiply it by an activity multiplier and you get your Total Daily Energy Expenditure (TDEE) — the realistic number of calories you burn in an average day, including movement and exercise:

Sedentary (little or no exercise): BMR × 1.2
Light (exercise 1–3 days/week): BMR × 1.375
Moderate (exercise 3–5 days/week): BMR × 1.55
Active (exercise 6–7 days/week): BMR × 1.725
Very Active (physical job or twice-daily training): BMR × 1.9

Setting a Calorie Target

Once you know your TDEE — your maintenance calories — adjusting it up or down is what actually drives weight change:

Goal	Typical Adjustment
Maintain weight	Eat at TDEE
Lose ~0.5 kg/week	TDEE − ~500 cal/day
Lose ~1 kg/week	TDEE − ~1,000 cal/day
Gain weight	TDEE + ~250–500 cal/day

Why 500 calories? one pound of body fat is roughly 3,500 calories. A daily deficit of 500 calories works out to about one pound (0.45 kg) lost per week — a pace generally considered sustainable.

Why These Numbers Are Estimates, Not Guarantees

BMR and TDEE formulas are population averages — they get most people within a reasonable range, but individual metabolism varies. Treat your calculated number as a starting point, track your actual results over a few weeks, and adjust from there.

Step-by-Step: Find Your Daily Calorie Needs

Enter your age, sex, height and weight (metric or imperial)
Choose the activity level that best matches your typical week
Review your BMR and maintenance calories (TDEE)
Use the lose/gain targets shown to set your daily goal

Try It Yourself

Use our free Calorie Calculator — BMR, TDEE and weight-goal targets

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