Calorie Calculator
0 calories/day to maintain weight
How Your Calorie Targets Are Calculated
This calculator first estimates your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation, the formula most widely recommended by dietitians for its accuracy across body types. Your BMR is then multiplied by an activity factor to estimate your Total Daily Energy Expenditure (TDEE), which is your maintenance calorie level. From there, the calculator applies the standard rule of thumb that a pound of body fat represents roughly 3,500 calories, so a sustained daily deficit or surplus of about 500 calories corresponds to roughly 1 pound of change per week. Weight loss targets below about 1,200 calories/day (women) or 1,500 calories/day (men) are generally not recommended without medical supervision, since very low intakes are hard to sustain and can affect nutrition and muscle mass.
Why Weight Loss Isn't Perfectly Linear
The 3,500-calorie-per-pound rule is a useful planning estimate, not a biological guarantee. As you lose weight, your BMR drops slightly because a smaller body needs less energy, so the same calorie deficit yields a bit less weight loss over time. Water retention, hormonal shifts, and muscle gain (if you strength train) can also mask or exaggerate week-to-week scale changes even when your calorie balance is on track. Treat these numbers as a starting point to adjust from based on your real-world results over several weeks, not as an exact prediction.
Related Tools
Want more detail on your energy expenditure and how activity level affects it? See the TDEE calculator. To fine-tune protein, carbs, and fat around whichever calorie target you choose, use the macro calculator. This tool provides an educational estimate only, not medical advice — talk to a doctor or registered dietitian before starting any weight-loss or weight-gain program, especially if you have an existing health condition.
Frequently Asked Questions
How many calories should I eat to lose 1 pound a week?
Eat roughly 500 calories per day below your maintenance level (your TDEE). Since 1 pound of body fat is roughly equal to 3,500 calories, a consistent 500-calorie daily deficit works out to about a 1-pound loss per week. This calculator shows that target automatically once you enter your details.
Why does this calculator ask for activity level separately from exercise calories?
The activity multiplier already accounts for your typical weekly movement, from sedentary to very active, so it estimates your total daily burn (TDEE) in one step rather than requiring you to log workouts separately. If your activity varies a lot week to week, choose the level that best reflects your average, or check the calories-burned-calculator for individual workouts.