Basal Metabolic Rate (BMR) Calculator
Estimate how many calories your body burns at rest, and optionally compute your daily calorie needs (TDEE).
Results
⚡ Overview: Basal Metabolic Rate (BMR) Calculator
The Basal Metabolic Rate (BMR) Calculator estimates the number of calories your body needs to maintain basic functions at rest — including breathing, circulation, and cell production. This personalized estimate helps determine your daily calorie needs and is essential for effective weight management, fitness planning, and metabolic health awareness.
Our tool supports both the Mifflin-St Jeor and Harris-Benedict equations, two of the most accurate and widely used formulas. It also allows you to select activity levels to estimate Total Daily Energy Expenditure (TDEE) and offers a macronutrient breakdown (protein, carbs, fat) with a visual chart for clarity.
📐 BMR Formulas & Methodology
This calculator uses the following scientifically validated equations:
Mifflin-St Jeor Formula
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Harris-Benedict Formula
Men: BMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) − (6.755 × age)
Women: BMR = 655.1 + (9.563 × weight in kg) + (1.85 × height in cm) − (4.676 × age)
After calculating BMR, your Total Daily Energy Expenditure (TDEE) is estimated using your selected activity multiplier. For example:
TDEE = BMR × Activity LevelCommon activity multipliers:
- Sedentary (little or no exercise): 1.2
- Lightly Active (1–3 days/week): 1.375
- Moderately Active (3–5 days/week): 1.55
- Very Active (6–7 days/week): 1.725
- Super Active (physical job or double training): 1.9
🧾 Example Calculation
Inputs:
- Unit System: Metric (kg, cm)
- Gender: Female
- Age: 30 years
- Weight: 65 kg
- Height: 170 cm
- Activity Level: Moderately Active (1.55)
- Formula: Mifflin-St Jeor
Step-by-step:
BMR = (10 × 65) + (6.25 × 170) − (5 × 30) − 161
BMR = 650 + 1062.5 − 150 − 161 = 1401.5 kcal/day
TDEE = 1401.5 × 1.55 = 2172.3 kcal/day
Macronutrient Breakdown (Default: 30% protein, 40% carbs, 30% fat):
- Protein: 162.9 g (652 kcal)
- Carbohydrates: 217.2 g (869 kcal)
- Fat: 72.4 g (652 kcal)
💡 Practical Use Cases
- 🍽️ Weight Loss: Set a calorie deficit goal based on your TDEE to lose fat safely.
- 🏋️ Fitness Planning: Align calorie intake with training and muscle gain goals.
- 🥗 Meal Prep: Balance protein, carbs, and fats based on your macro breakdown.
- 📈 Health Tracking: Monitor metabolic changes over time with consistent inputs.
- 📊 Diet Coaching: Use the BMR benchmark to advise clients on intake adjustments.
❓ Frequently Asked Questions (FAQ)
What is BMR and why is it important?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest. Knowing your BMR helps you estimate daily calorie needs and adjust intake for weight gain, loss, or maintenance.
Which BMR formula is more accurate?
The Mifflin-St Jeor formula is considered more accurate for modern populations. However, Harris-Benedict may still be useful for comparing historical datasets or validating older tools.
Should I include activity level?
Yes. Including your activity level transforms your BMR into your TDEE (Total Daily Energy Expenditure), which reflects your real daily energy needs.
How can I use my BMR to lose weight?
Subtract ~500 kcal/day from your TDEE to aim for ~0.5 kg (1 lb) weight loss per week — a sustainable and safe fat loss pace.
Is BMR the same as TDEE?
No. BMR measures your energy needs at rest, while TDEE includes daily activities. TDEE = BMR × activity multiplier.
What are macronutrients and how are they calculated?
Macronutrients include protein, carbohydrates, and fats. The calculator uses a common split (30% protein, 40% carbs, 30% fat) to show grams and kcal based on your TDEE.
Can I customize the macro ratio?
Currently, the calculator uses a fixed 30/40/30 ratio, but we plan to add customizable macro presets (e.g., Keto, Balanced, High-Protein) in a future update.
Does this calculator support both metric and imperial units?
Yes! You can switch between kg/cm and lbs/in using the "Unit System" dropdown. All calculations are internally converted to metric.
What is a healthy BMR range?
BMR typically ranges from 1200 to 2200 kcal/day for most adults. Our tool includes a visual indicator to show where your BMR sits compared to average male/female BMRs.
How often should I recalculate my BMR?
Recalculate your BMR if your weight, age, activity level, or body composition changes significantly.
📘 Understanding BMR vs TDEE vs Calories
- BMR (Basal Metabolic Rate): Your body’s minimum energy needs at rest.
- TDEE (Total Daily Energy Expenditure): BMR × your activity level.
- Calories: Unit of energy used in food labeling and energy consumption.
Knowing these distinctions helps tailor your diet, training, and health strategies with precision.