Calorie Calculator
Find your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) based on your age, weight, height and how active you are. Then set a goal (lose, maintain or gain) and get a daily calorie target with a rough macro split. All calculations use the Mifflin-St Jeor equation, the most accurately validated formula for most adults.
Explain like I'm 5 (calories and why they matter)
Calories are a measure of energy. Your body burns a certain number just to stay alive: breathing, pumping blood, keeping warm. Move around and you burn more. If you eat more than you burn, your body stores the extra as fat. If you eat less, it uses stored fat for fuel. This calculator works out your personal burn rate so you know what you're working with.
Calculate
Enter your details and press Calculate.
Your numbers
- BMR (calories at rest)–
- TDEE (daily burn)–
- Daily calorie target–
Rough macro split
- Protein (30%)–
- Carbohydrates (40%)–
- Fat (30%)–
Time to goal
- Estimated weeks–
- Estimated months–
Your calculated target was below the safe minimum. The target shown is the recommended floor for your sex.
Prove it
Mifflin-St Jeor: male BMR = 10W + 6.25H \u2212 5A + 5; female = 10W + 6.25H \u2212 5A \u2212 161. TDEE = BMR × activity multiplier. Goal adjustments: \u22121500 to +500 kcal/day. Macros: 30% protein (4 kcal/g), 40% carbs (4 kcal/g), 30% fat (9 kcal/g).
Useful? Press Ctrl + D to bookmark.
BMR, TDEE and why they are different
Your BMR (Basal Metabolic Rate) is the number of calories your body burns just to function at complete rest: heart beating, lungs breathing, organs working, body temperature maintained. For most people, BMR accounts for 60–75% of total daily calorie burn.
TDEE (Total Daily Energy Expenditure) takes BMR and scales it by an activity multiplier. A sedentary desk worker might burn their BMR times 1.2. A construction worker who also trains five days a week might be closer to 1.9. The multipliers used here (1.2 to 1.9) are the standard Harris-Benedict activity factors.
How to use these numbers
If you want to lose weight, eat consistently below your TDEE. A 500 kcal daily deficit produces roughly 0.5 kg of fat loss per week (based on fat providing approximately 7,700 kcal/kg). A 250 kcal deficit is slower but often more sustainable. Going much below 1,200 kcal for women or 1,500 kcal for men is not recommended without medical supervision, which is why this calculator imposes a floor.
If you want to gain weight, eat above your TDEE. A surplus of 250–500 kcal/day is a reasonable rate for muscle gain with controlled fat gain. Larger surpluses mostly add fat.
Why the numbers might not match your experience
The Mifflin-St Jeor equation is the most accurate general formula available, but it is still an estimate. Actual BMR varies by muscle mass, hormonal status, gut microbiome, sleep quality and more. The activity multiplier is also self-reported and notoriously hard to judge accurately. Use the output as a starting point. Track your weight for two or three weeks at the target calorie level, then adjust by 100–200 kcal up or down based on what actually happens.
Nothing here is medical or dietary advice. If you have a health condition that affects your metabolism (thyroid issues, diabetes, a history of eating disorders), talk to your GP or a registered dietitian before making significant changes to your eating.
Related calculators
Calories are one input. Here are the neighbours.
Frequently asked questions
What is BMR and how is it calculated?
BMR is the calories your body needs at complete rest. This calculator uses the Mifflin-St Jeor equation: male BMR = 10W + 6.25H − 5A + 5; female BMR = 10W + 6.25H − 5A − 161, where W = weight in kg, H = height in cm, A = age in years.
What is TDEE?
Total Daily Energy Expenditure. Your BMR multiplied by an activity factor. It represents the total calories you burn in a day. Eat at TDEE to maintain weight, below it to lose, above it to gain.
How much of a calorie deficit should I aim for?
Around 500 kcal/day produces roughly 0.5 kg/week fat loss, which is a sustainable rate for most people. A 250 kcal deficit is gentler and often easier to maintain. Larger deficits risk muscle loss and are harder to stick to.
Are the macro splits accurate?
They are a general starting point (30% protein, 40% carbs, 30% fat). Optimal splits depend on your training type, goals and health. Strength athletes often benefit from more protein. Treat these as a rough guide, not a prescription.