Three numbers decide your calorie target: what your body burns at rest, how active you actually are, and how fast you want to change. Guessing any one of them throws off the other two.
Free health tool
Calorie Calculator
Your daily calorie target for maintaining, losing or gaining weight, with a macro breakdown, based on Mifflin-St Jeor plus your real activity level.
A 1,000 kcal/day swing is aggressive. Sustainable results usually come from the mild or standard options, and a very low intake needs medical supervision.
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Where these numbers actually come from
Your Basal Metabolic Rate (BMR) is calculated with the Mifflin-St Jeor equation, then multiplied by an activity factor to get your Total Daily Energy Expenditure (TDEE), the calories you burn in an average day including movement and exercise, not just resting. Your goal then adds or subtracts a daily deficit or surplus from that TDEE: roughly 7,700 kcal equals a kilogram of body fat, so a 500 kcal/day deficit works out to about half a kilogram lost per week, if everything else about your metabolism holds steady, which in reality it rarely does exactly. The macro split shown (40% carbs, 30% protein, 30% fat by calories) is a reasonable general starting point, not a prescription, adjust it based on your own goals, training style, or a dietitian's advice.
Calorie calculator FAQ
How many calories should I eat to lose weight?
Start from your TDEE (maintenance calories) and subtract a deficit, 250 to 500 kcal a day is a sustainable, commonly recommended range that works out to roughly 0.25 to 0.5 kg of loss a week, since about 7,700 kcal equals one kilogram of body fat.
What is TDEE?
Total Daily Energy Expenditure: your BMR multiplied by an activity factor, an estimate of everything you burn in a full day including exercise and everyday movement, not just resting metabolism.
Which activity level should I pick?
Be honest rather than aspirational. "Sedentary" means a desk job with little deliberate exercise, "Moderate" means real structured exercise 3 to 5 days a week, and "Very active" is reserved for a physically demanding job or serious daily training, most people overestimate which bracket they are actually in.
Is the 40/30/30 macro split a strict requirement?
No, it is a reasonable general-purpose starting point, not a prescription. Strength athletes often run higher protein, endurance athletes often run higher carbohydrate, and personal preference and medical guidance both matter more than any single default split.
Is a 1,000 calorie a day deficit or surplus safe?
That is an aggressive swing, roughly a kilogram a week, and sustained very low intakes can risk muscle loss, nutrient deficiency and metabolic slowdown. The calculator flags this option with a warning; a doctor or registered dietitian should be involved before pursuing changes at that pace.
Is my data private?
Yes. Every calculation runs in your browser. Nothing you enter is sent to a server, logged, or stored.
Free calorie calculator by ANUPRESS
Be honest about your activity level, not aspirational
This is the single most common place people overestimate. “Moderate” activity means real structured exercise 3 to 5 days a week, not a desk job with occasional weekend walks, and picking a bracket you’re aspiring to rather than the one you’re actually living in inflates your calorie target and quietly stalls progress. If you’re unsure, round down, it’s a smaller error to correct than rounding up.
Why the deficit size matters more than people think
About 7,700 kcal roughly equals a kilogram of body fat, which is where the standard 250 to 500 kcal daily deficit options come from, they translate to a genuinely sustainable 0.25 to 0.5 kg a week. Going further isn’t automatically faster progress in practice: very low intakes are harder to sustain, tend to cost more muscle alongside fat, and the 1,000 kcal option here comes with an explicit warning for exactly that reason.
The macro split is a starting point, not a rule
The default 40% carbohydrate, 30% protein, 30% fat split shown alongside your calorie target is a reasonable general-purpose baseline, useful if you have no other guidance, not a number handed down from anywhere authoritative. Strength training usually benefits from higher protein, medical conditions can require a different balance entirely, and a registered dietitian’s specific guidance always outranks a generic default.