Body Mass Index & Metabolic Fitness Calculator

BMI is calculated using the formula: Weight in kilograms divided by Height in meters squared (kg/m²). For example, a person weighing 70 kg with a height of 1.75 meters has a BMI of 70 / (1.75 × 1.75) = 22.86 kg/m². For imperial measurements, the formula is: [Weight (lbs) × 703] / [Height (inches)²].

South Asian individuals naturally have a higher percentage of body fat and visceral fat around internal organs compared to other ethnicities with the same BMI. As a result, the risk for Type-2 Diabetes, cardiovascular disease, and metabolic syndrome increases at a lower threshold (BMI 23.0 instead of 25.0).

BMI (Body Mass Index) evaluates weight relative to height.
BMR (Basal Metabolic Rate) is the baseline calories your body expends purely at rest to sustain brain, heart, and lung function.
TDEE (Total Daily Energy Expenditure) is your total daily calorie burn when accounting for your daily physical activity and gym workouts. Eating below TDEE leads to fat loss; eating above TDEE with resistance training promotes muscle hypertrophy.

BMI only looks at total body scale weight and cannot distinguish between dense lean muscle tissue and fat. A 5'10" competitive bodybuilder weighing 90 kg with 10% body fat will register a BMI of 28.5 (technically "Overweight"), even though they are extremely lean and physically fit. In strength training communities, skinfold calipers, DEXA scans, and waist-to-height ratio are superior body composition indicators.

Fitness trainers can use this calculator as a standard baseline screening during new member consultations. By showing members their estimated daily maintenance calories and suggested weight goals, coaches can build structured workout programs and nutrition plans. FitStack provides gyms with centralized member tracking so transformation milestones can be celebrated and recorded.