Calorie Calculator
Calculate your daily calorie needs using the Mifflin-St Jeor formula. Find your BMR and TDEE for weight loss or gain.
Calculation Inputs
Results computed instantly — your data never leaves your device.
Live Results
Real-TimeMaintenance Calories
2,633 kcal
BMR (base metabolic rate)
1,699 kcal
TDEE
2,633 kcal
Calorie Goals
How to Use the Calorie Calculator
- 1
Select your unit system (metric or imperial) and gender.
- 2
Enter your age, weight, and height.
- 3
Choose your activity level from the dropdown — be honest for accurate results.
- 4
The calculator displays your BMR, TDEE, and a complete goal table for weight loss and gain.
Formula & Mathematical Basis
Variable Key
BMRBasal Metabolic Rate — calories burned at complete rest
TDEETotal Daily Energy Expenditure — BMR scaled by activity level
Activity FactorSedentary 1.2 · Light 1.375 · Moderate 1.55 · Active 1.725 · Very Active 1.9
weightBody mass in kilograms
heightStature in centimetres
ageAge in whole years
📝 The Mifflin-St Jeor equation (1990) is consistently shown to be the most accurate BMR predictor for the general population in systematic reviews. The older Harris-Benedict formula (1919, revised 1984) overestimates by ~5% on average.
Step-by-Step Examples
Moderately active 30-year-old male
Scenario: Male, age 30, 80 kg, 180 cm, exercises 3–5 days/week.
- 1.BMR = 10×80 + 6.25×180 − 5×30 + 5 = 800 + 1,125 − 150 + 5 = 1,780 kcal.
- 2.Activity factor (moderate): 1.55.
- 3.TDEE = 1,780 × 1.55 = 2,759 kcal.
- 4.Weight loss target (−0.5 kg/wk): 2,759 − 500 = 2,259 kcal/day.
Sedentary 45-year-old female
Scenario: Female, age 45, 65 kg, 165 cm, desk job, minimal activity.
- 1.BMR = 10×65 + 6.25×165 − 5×45 − 161 = 650 + 1,031.25 − 225 − 161 = 1,295 kcal.
- 2.Activity factor (sedentary): 1.2.
- 3.TDEE = 1,295 × 1.2 = 1,554 kcal.
Practical Use Cases
- Creating a personalised caloric deficit plan for sustainable weight loss
- Sports nutrition — calculating energy requirements for endurance training phases
- Post-bariatric surgery dietary planning under medical supervision
- Bulking and cutting cycles for strength athletes
- Estimating caloric needs during pregnancy or breastfeeding as a starting point
- Corporate wellness programs for population-level nutritional guidance
Common Pitfalls
- Choosing an activity level that is too high — most people overestimate exercise intensity and duration.
- Eating at BMR (not TDEE) — the BMR is the floor of survival metabolism, not a diet target.
- Ignoring adaptive thermogenesis — metabolism slows during prolonged caloric restriction, requiring re-calculation every 4–6 weeks.
- Assuming the 3,500-calorie-per-pound rule is linear — it breaks down over long periods due to metabolic adaptation.
- Not accounting for muscle mass changes when body weight shifts significantly.
Frequently Asked Questions
What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to maintain basic functions like breathing and circulation. It is calculated using the Mifflin-St Jeor formula.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. It represents the total calories you burn per day including exercise and daily movement.
How many calories should I eat to lose weight?
A deficit of 500 calories/day below your maintenance level leads to approximately 0.5 kg (1 lb) of weight loss per week. Our calculator shows exact targets for mild, moderate, and aggressive weight loss.
What activity level should I choose?
Sedentary = desk job, no exercise. Light = 1–3 days/week exercise. Moderate = 3–5 days/week. Active = 6–7 days/week. Very Active = hard exercise twice per day or a physical job.
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