Calorie Calculator

How many calories do you need?

Your daily calorie needs depend on your size, age, sex and how active you are. This calculator uses the Mifflin-St Jeor equation — currently considered one of the most accurate predictive formulas — to estimate your Basal Metabolic Rate, then scales it by an activity factor to find the calories that keep your weight steady.

Using the results

• Maintain: eat around this number to stay at your current weight.
• Lose weight: a 250–500 kcal daily deficit yields gradual, sustainable loss.
• Gain weight: a 250–500 kcal surplus supports steady muscle or weight gain.
• BMR floor: avoid eating far below your BMR for long periods.

Tips for accuracy

Be honest about your activity level — most people overestimate it. Track your weight over two to three weeks and adjust your intake up or down by 100–200 kcal if the scale isn't moving the way you expect. Formulas give a starting point; your own results are the real guide.

Frequently asked questions

How are my daily calories calculated?

We first estimate your Basal Metabolic Rate (BMR) — the energy your body uses at rest — with the Mifflin-St Jeor equation, then multiply by an activity factor to get your Total Daily Energy Expenditure (TDEE), the calories needed to maintain your current weight.

What is the difference between BMR and TDEE?

BMR is what you'd burn lying in bed all day. TDEE adds the calories you burn through daily movement and exercise. TDEE is the number to use for maintenance; BMR is a useful floor you generally shouldn't eat below.

How much should I eat to lose or gain weight?

A deficit of about 500 kcal/day tends to produce roughly 0.5 kg (1 lb) of weight loss per week; a 500 kcal surplus does the reverse. This tool shows mild (±250) and standard (±500) targets so you can pick a sustainable pace.

Is this medical advice?

No. These are estimates based on population formulas and individual needs vary. For personalized nutrition or any medical condition, consult a doctor or registered dietitian.