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Calculate calories
Find out how many calories you need per day based on your details and activity level.
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Calculate calories
Our free calorie calculator uses the Mifflin-St Jeor equation — the most accurate formula available — to calculate how many calories you need per day based on your age, sex, height, weight and activity level. It shows your Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), and calorie targets for different goals from weight loss to weight gain.
The Mifflin-St Jeor formula calculates your Basal Metabolic Rate (BMR) — the calories your body needs at complete rest. For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. This is then multiplied by your activity level to get your TDEE.
The average adult needs around 2,000–2,500 calories per day to maintain their weight, but this varies significantly based on age, sex, height, weight and activity level. Use our calculator to get a personalised figure.
A calorie deficit occurs when you consume fewer calories than your body burns. A deficit of 500 calories per day typically results in approximately 0.5kg (1 lb) of weight loss per week, as roughly 3,500 calories equals 0.45kg of fat.
BMR is the number of calories your body burns at complete rest just to maintain basic functions — breathing, circulation, cell production. It accounts for about 60–75% of your total daily calorie expenditure.
TDEE is the total calories you burn per day including activity. It's calculated by multiplying your BMR by an activity factor — from sedentary (×1.2) to extra active (×1.9). This is the number to base your diet on.
To lose weight, eat fewer calories than your TDEE. A moderate deficit of 300–500 calories per day is sustainable and leads to gradual weight loss of 0.3–0.5kg per week without excessive hunger.
Macros are the three main nutrients: carbohydrates (4 kcal/g), protein (4 kcal/g) and fat (9 kcal/g). A balanced split is roughly 40% carbs, 30% protein and 30% fat — though optimal ratios depend on your goals.