Fitness Calculator: Calculate BMI, BMR, TDEE & Body Fat %

Welcome to our online Fitness Data Calculator! Whether your goal is fat loss, weight maintenance, or muscle gain, understanding your Total Daily Energy Expenditure (TDEE) and Basal Metabolic Rate (BMR) is the essential first step.

Simply input your age, height, weight, gender, and daily activity level to calculate your personalized health metrics.

BMI Score

Est. Body Fat

--%

BMR (Basal Metabolic Rate)

kcal/day

TDEE (Total Daily Energy Expenditure)

kcal/day

Weight Loss (-15% deficit)

kcal/day

Muscle Gain (+10% surplus)

kcal/day

💡 Disclaimer & Accuracy Notice

This calculator uses the Mifflin-St Jeor equation for estimations. Results are for fitness and nutritional planning purposes only and do not replace professional medical advice. Individual factors like body composition, muscle mass, and hormone levels affect real energy expenditure; adjust your intake based on actual progress.

📘 Understanding Your Results

1. BMI (Body Mass Index)

BMI is an international standard used to classify weight status in adults.

Formula: BMI = Weight (kg) / Height (m)⁺
Categories: Underweight (< 18.5), Normal (18.5 ~ 24.9), Overweight (25 ~ 29.9), and Obese (≥ 30).

2. BMR (Basal Metabolic Rate)

BMR is the minimum amount of energy (calories) your body needs to stay alive at rest (e.g., breathing, pumping blood, maintaining body temperature).

Formula Used: We utilize the Mifflin-St Jeor Equation, which is widely considered one of the most accurate equations for estimating modern adult metabolic rates.

3. TDEE (Total Daily Energy Expenditure)

TDEE represents the total number of calories you burn in a 24-hour period, factoring in your BMR plus physical activity and daily movement.

For Fat Loss: Aim for a moderate caloric deficit of ~15% below your TDEE (TDEE × 0.85).
For Muscle Gain: Target a slight caloric surplus of ~10% above your TDEE (TDEE × 1.10) alongside progressive resistance training.

4. Estimated Body Fat %

Estimated using the Deurenberg Formula, incorporating BMI, age, and gender. While specialized equipment like DEXA scans or calipers provide precise measurements, this estimation offers a quick and practical baseline for tracking overall body composition.