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Fitness & Health

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-Time

Maintenance Calories

2,633 kcal

BMR (base metabolic rate)

1,699 kcal

TDEE

2,633 kcal

100% Client-SidePrivate & Secure

Calorie Goals

Extreme Weight Loss (−1 kg/wk)1,633 kcal
Weight Loss (−0.5 kg/wk)2,133 kcal
Mild Weight Loss (−0.25 kg/wk)2,383 kcal
Maintain Weight2,633 kcal
Mild Weight Gain (+0.25 kg/wk)2,883 kcal
Weight Gain (+0.5 kg/wk)3,133 kcal

How to Use the Calorie Calculator

  1. 1

    Select your unit system (metric or imperial) and gender.

  2. 2

    Enter your age, weight, and height.

  3. 3

    Choose your activity level from the dropdown — be honest for accurate results.

  4. 4

    The calculator displays your BMR, TDEE, and a complete goal table for weight loss and gain.

Formula & Mathematical Basis

BMR (male) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 BMR (female) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161 TDEE = BMR × Activity Factor

Variable Key

BMR

Basal Metabolic Rate — calories burned at complete rest

TDEE

Total Daily Energy Expenditure — BMR scaled by activity level

Activity Factor

Sedentary 1.2 · Light 1.375 · Moderate 1.55 · Active 1.725 · Very Active 1.9

weight

Body mass in kilograms

height

Stature in centimetres

age

Age 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

1

Moderately active 30-year-old male

Scenario: Male, age 30, 80 kg, 180 cm, exercises 3–5 days/week.

  1. 1.BMR = 10×80 + 6.25×180 − 5×30 + 5 = 800 + 1,125 − 150 + 5 = 1,780 kcal.
  2. 2.Activity factor (moderate): 1.55.
  3. 3.TDEE = 1,780 × 1.55 = 2,759 kcal.
  4. 4.Weight loss target (−0.5 kg/wk): 2,759 − 500 = 2,259 kcal/day.
✅ Maintenance: 2,759 kcal. Mild weight loss: 2,259 kcal/day.
2

Sedentary 45-year-old female

Scenario: Female, age 45, 65 kg, 165 cm, desk job, minimal activity.

  1. 1.BMR = 10×65 + 6.25×165 − 5×45 − 161 = 650 + 1,031.25 − 225 − 161 = 1,295 kcal.
  2. 2.Activity factor (sedentary): 1.2.
  3. 3.TDEE = 1,295 × 1.2 = 1,554 kcal.
✅ Maintenance: 1,554 kcal/day. Caloric floor for safe loss: ~1,200 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 Mistakes to Avoid

  • 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.

Glossary of Terms

BMR (Basal Metabolic Rate)
The minimum calories needed to sustain vital organ function at complete rest in a thermoneutral environment.
TDEE (Total Daily Energy Expenditure)
Total calories burned per day including physical activity, exercise, and the thermic effect of food.
Mifflin-St Jeor Equation
A validated predictive equation for BMR published in 1990 by MD Mifflin et al., recommended by the Academy of Nutrition and Dietetics.
Thermic Effect of Food (TEF)
The energy cost of digesting and metabolising food — approximately 10% of total caloric intake for mixed diets.
Caloric Deficit
Consuming fewer calories than TDEE, forcing the body to oxidise stored fat and glycogen for energy.
Adaptive Thermogenesis
The metabolic slowdown that occurs during sustained caloric restriction, a survival response that reduces TDEE beyond what weight loss alone predicts.

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.

Sources & References

  1. [1]
  2. [2]
    Comparison of Predictive Equations for BMR— Journal of the American Dietetic Association, 2005
  3. [3]
    Dietary Reference Intakes for Energy— National Academies of Sciences, Engineering, and Medicine, 2023

CalculatorFree Nutrition TeamRegistered Dietitian & Exercise Science Review

Formula validated against clinical literature; reviewed by nutrition professionals.

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