Enter your details once — instantly calculate BMI, TDEE, daily calorie needs, macronutrient breakdown, body fat percentage, ideal body weight, and water intake. No sign-up. No ads. Just accurate health metrics.
Understanding your body's unique health metrics is the foundation of any successful fitness or weight management plan. This free health calculator uses clinically recognized formulas — including the Mifflin-St Jeor equation for BMR, the US Navy method for body fat, ISSN/ACSM weight-anchored protein targets for macronutrients, and the Devine, Robinson, Miller, and Hamwi formulas for ideal body weight — to deliver seven personalized metrics in seconds.
Whether you want to lose weight, build muscle, or simply understand your caloric needs, knowing your TDEE (Total Daily Energy Expenditure) and optimal macro split gives you a science-backed starting point — not a generic guess.
All calculations run entirely in your browser. Your personal data is never stored, shared, or transmitted. Results update instantly and support both metric (kg/cm) and imperial (lbs/inches) units.
BMI is a widely used screening tool that compares your weight to your height. A healthy BMI range is 18.5 – 24.9. While BMI doesn't account for muscle mass or fat distribution, it remains a reliable first indicator of weight-related health risk.
TDEE is the total number of calories your body burns per day, factoring in your activity level. It's the single most important number for weight management — eat at TDEE to maintain, below to lose, and above to gain.
Macronutrients are the three main sources of dietary energy. This calculator anchors protein to your body weight per ISSN/ACSM guidelines, sets a minimum fat intake to cover essential fatty acid needs, and fills remaining calories with carbohydrates — the scientifically correct method.
BMR is the number of calories your body needs to sustain basic functions at complete rest — breathing, circulation, and cell repair. It represents your absolute minimum caloric floor and should never be your daily intake target.
Body fat % is a more precise health indicator than BMI because it separates lean mass from fat mass. Calculated using the US Navy circumference method (waist, neck, and hip measurements), healthy ranges are 10–20% for men and 18–28% for women.
Hydration needs are calculated based on body weight and activity level per EFSA 2010 guidelines. Adequate water intake supports metabolism, cognitive performance, and physical endurance. This calculator provides a personalized daily target in liters and glasses.
Common questions about BMI, TDEE, calories, macros, body fat & water intake.
CalcPlex's free health calculator is the most comprehensive all-in-one health metrics tool available online — no registration, no fees, no data collection. In a single session, you can calculate your Body Mass Index (BMI), Total Daily Energy Expenditure (TDEE), Basal Metabolic Rate (BMR), daily calorie targets, macronutrient breakdown, body fat percentage, ideal body weight, and daily water intake — all from one input form.
Unlike basic single-metric tools, this calculator combines seven clinically validated health metrics into a unified dashboard. Every calculation is powered by the same peer-reviewed formulas used by nutritionists, personal trainers, and healthcare providers: the Mifflin-St Jeor equation for metabolic rate, the US Navy circumference method for body composition, a four-formula consensus (Devine, Robinson, Miller, Hamwi) for ideal weight estimation, and ISSN/ACSM weight-anchored protein targets for scientifically accurate macronutrient distribution. Supports both metric (kg/cm) and imperial (lbs/inches) units.
Whether your goal is weight loss, muscle gain, improving body composition, or simply understanding your baseline health numbers, this tool gives you an accurate, personalised starting point in under 30 seconds — with no account required and zero data ever leaving your device.
Macronutrients — protein, carbohydrates, and fat — are the three calorie-containing nutrients your body requires in large amounts daily. Unlike micronutrients (vitamins and minerals), macros directly determine your energy balance, body composition, and metabolic rate. Getting your macro split right is arguably more important than hitting a calorie number alone.
Essential for muscle repair, hormone synthesis, and satiety. Per ISSN guidelines: 1.6–2.4 g/kg body weight depending on your goal. Higher during fat loss to preserve lean mass.
↗ ISSN Protein Position PaperYour body's preferred fuel source, especially for high-intensity exercise. Per the USDA Dietary Guidelines, 45–65% of total calories from carbs is the general population target. This calculator fills carbs after protein and fat are set.
↗ USDA Dietary Guidelines 2020–2025Critical for hormone production, fat-soluble vitamin absorption (A, D, E, K), and brain function. A minimum of 0.7 g/kg covers essential fatty acid (EFA) needs per Dietary Reference Intake (DRI) guidelines.
↗ NIH DRI for Fats & Fatty AcidsEvery metric in this calculator is grounded in peer-reviewed clinical research. Below are the primary sources and authoritative external guides for each formula used.
Protein targets (1.6–2.4 g/kg body weight) are set per the International Society of Sports Nutrition (ISSN) and American College of Sports Medicine (ACSM) joint position statements. Fat minimums (0.7 g/kg) follow the Dietary Reference Intakes (DRI) for essential fatty acids. Carbohydrates fill remaining caloric needs.
The Mifflin-St Jeor equation (1990) is validated as the most accurate BMR predictor for the general population. Published in the American Journal of Clinical Nutrition, it outperforms the older Harris-Benedict revision in multiple comparative studies.
The WHO BMI classification (Underweight <18.5 · Normal 18.5–24.9 · Overweight 25–29.9 · Obese ≥30) is the global standard for population-level weight-related health screening. The CDC and NHS publish the same thresholds for adults.
Developed by Hodgdon & Beckett (1984) for the US Navy, this method estimates body fat from neck, waist, and hip circumferences. It has a validated accuracy of ±3–4% vs DEXA scans — the gold standard in clinical body composition measurement.
The European Food Safety Authority (EFSA) 2010 adequate intake values recommend 35 ml/kg body weight as the baseline hydration target for adults. The National Academies of Medicine independently recommends 3.7 L/day for men and 2.7 L/day for women from all sources, consistent with the weight-based approach used here.
This calculator averages four validated clinical formulas — Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) — to produce a more robust ideal weight range than any single formula alone. All four were originally developed for clinical pharmacokinetics and medication dosing.
All calculations use established, peer-reviewed formulas: Mifflin-St Jeor (BMR/TDEE), US Navy Circumference Method (body fat %), Devine, Robinson, Miller & Hamwi (ideal weight range), and ISSN/ACSM weight-anchored targets (macronutrients). Results are estimates for healthy adults aged 15–100 and are provided for informational and educational purposes only. For personalised medical or nutritional advice, consult a qualified healthcare professional.
More free calculators on CalcPlex: Finance Calculators · Math Tools · Unit Converter · Education Tools · Pakistan Calculators