BMR Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Supports Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas.
Body parameters
Calculated Energy Outputs
Recommended Target Calorie Ranges
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How to Use BMR Calculator
BMR Calculator Formula / How It Works
This calculator runs selected BMR formulas using weight, height, and age parameters. If body fat % is present in Katch mode, it derives LBM and uses it as the sole metabolic multiplier. TDEE is computed by applying activity multipliers (1.2 to 1.9).
For example, a 25-year-old male weighing 70kg at 175cm height has a BMR of approximately 1,630 kcal/day under Mifflin-St Jeor.
Frequently Asked Questions
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic functions — breathing, circulation, cell production, and temperature regulation. This calculator estimates your BMR using either the Mifflin-St Jeor or Harris-Benedict equation.
BMR is the calories you burn doing nothing (at rest). TDEE (Total Daily Energy Expenditure) is BMR multiplied by your activity level — it represents the total calories you burn per day including exercise and movement. Multiply your BMR by an activity multiplier to get TDEE.
This calculator uses the Mifflin-St Jeor equation (published 1990), which is considered the most accurate for most adults: BMR = (10 × weight kg) + (6.25 × height cm) – (5 × age) + 5 (men) or –161 (women). It is within 10% of measured BMR for most people.
Multiply your BMR by an activity factor: 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active), or 1.9 (extremely active). The result is your TDEE — the calories needed to maintain your current weight. Eat less to lose weight; more to gain.
The Mifflin-St Jeor equation is accurate to within ±10% for most healthy adults. Accuracy decreases for very muscular individuals (tends to underestimate) or very obese individuals (tends to overestimate). For clinical accuracy, use indirect calorimetry measured by a healthcare professional.
Related Tools
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This free online TDEE Calorie Calculator supports both Metric (kg/cm) and Imperial (lbs/ft/in) inputs and calculates your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation. View 4 personalised calorie goal cards: Maintain, Mild Loss (−250 kcal), Cut (−500 kcal), and Extreme Cut (−1000 kcal) — each with built-in minimum intake floor protection. All results are computed client-side for complete privacy.
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