Fitness & Health Calculators
Welcome to the fitness & health calculator hub. Whether you’re tracking your BMI, figuring out your daily calorie needs, or estimating body fat percentage, these free tools give you clear, science-based answers in seconds — no sign-up, no email, no fine print.
Body Composition Calculators
Analyze body metrics, fat distribution, and overall physical composition using medical and fitness formulas.
BMI Calculator
Calculate Body Mass Index, WHO category, Prime BMI & healthy weight target.
Body Fat Calculator
US Navy method to estimate body fat percentage and fat vs lean mass.
Army Body Fat Calculator
Official US Army Regulation 600-9 tape test standards and pass/fail assessment.
Lean Body Mass Calculator
Determine fat-free mass using Boer, James, and Hume comparative formulas.
Ideal Weight Calculator
Compare Robinson, Miller, Devine, and Hamwi medical ideal weight formulas.
Healthy Weight Calculator
Find healthy body weight range based on normal BMI (18.5 – 24.9).
Overweight Calculator
Assess excess weight, required calorie deficit, and safe weight loss timeline.
Anorexic BMI Calculator
WHO clinical malnutrition & thinness grading with medical risk indicators.
Body Type Calculator
Identify your Somatotype (Ectomorph, Mesomorph, Endomorph) and frame size.
Body Surface Area Calculator
Calculate total body surface area (BSA) via Mosteller, Du Bois, and Boyd.
Waist-to-Hip Ratio Calculator
Evaluate visceral fat distribution, WHR and waist-to-height cardiovascular risk.
Calorie & Nutrition Calculators
Plan daily energy intake, macronutrient targets, and hydration strategies for weight management and performance.
Calorie Calculator
Daily caloric needs for weight maintenance, fat loss, or muscle gain.
BMR Calculator
Basal Metabolic Rate via Mifflin-St Jeor, Harris-Benedict & Katch-McArdle.
TDEE Calculator
Total Daily Energy Expenditure breakdown across BMR, NEAT, TEF, and exercise.
Macro Calculator
Custom grams and calories for Protein, Carbohydrates, and Fats by goal.
Carbohydrate Calculator
Target daily carb grams based on training volume, intensity, and sport.
Protein Calculator
Optimal daily protein intake for hypertrophy, maintenance, or fat loss.
Fat Intake Calculator
Healthy dietary fat requirements for hormonal support and cellular health.
Weight Watcher Points Calculator
Calculate SmartPoints value from calories, saturated fat, sugar, and protein.
Hydration Tracking Calculator
Personalized daily fluid intake based on body mass, climate, and exercise sweat.
Electrolyte & Sweat Loss Calculator
Calculate hourly sweat rate, sodium loss, and post-workout rehydration fluid.
Intermittent Fasting Calculator
Plan eating windows (16:8, 18:6, 20:4) and track autophagy & ketosis stages.
Fitness & Performance Calculators
Measure exercise performance, training intensity, and recovery metrics to optimize athletic output.
Pace Calculator
Calculate running pace, speed, race finish projections (5K, 10K, Marathon).
Calories Burned Calculator
MET-based energy expenditure for 35+ sports and daily physical activities.
One Rep Max Calculator
Estimate 1RM using Brzycki and Epley formulas with complete percentage chart.
Target Heart Rate Calculator
Determine 5 aerobic and anaerobic cardio training zones using Karvonen formula.
Heart Rate Variability (HRV) Calculator
Analyze rMSSD & ln(rMSSD) recovery readiness score and autonomic balance.
VO2 Max Calculator
Estimate aerobic capacity via Rockport 1-Mile Walk or Cooper 12-Min Run test.
Creatine Dosage Calculator
Calculate personalized loading and maintenance dosage protocols and timeline.
Weight Loss Timeline Calculator
Project exact milestone dates to reach goal weight based on daily caloric deficit.
Pregnancy & Fertility Calculators
Track gestational progress, ovulation windows, and reproductive health milestones with clinical accuracy.
Pregnancy Calculator
Gestational age, trimester tracking, developmental milestones & baby size.
Pregnancy Weight Gain Calculator
IOM guidelines for weekly and total healthy weight gain based on pre-pregnancy BMI.
Pregnancy Conception Calculator
Estimate probable conception window and fertile intercourse dates from due date.
Due Date Calculator
Naegele’s rule calculation from LMP, conception date, or IVF transfer.
Ovulation Calculator
Predict ovulation day, fertile window (5 days pre-ovulation), and luteal phase.
Conception Calculator
Optimal conception calendar, peak intercourse days, and earliest test dates.
Period Calculator
Forecast future menstrual cycles, cycle regularities, and next period dates.
Wellness & Medical Calculators
Monitor vital health indicators, lifestyle factors, and clinical risk markers for preventive care.
GFR Calculator
2021 CKD-EPI Creatinine equation for Glomerular Filtration Rate & kidney stage.
Sleep Cycle Analysis Calculator
90-minute ultradian sleep cycle calculator to wake up alert without grogginess.
Blood Pressure & MAP Calculator
AHA blood pressure classification and Mean Arterial Pressure (MAP) calculation.
Caffeine Half-Life Calculator
Track caffeine decay in bloodstream and determine optimal bedtime cutoff.
How to Use Our Fitness & Health Calculators
You don’t need a medical degree or a fitness app subscription to get useful answers here. Each tool follows the same simple flow:
- Pick your calculator. Start with the one closest to your goal — weight, calories, body fat, or performance.
- Enter your numbers. Height, weight, age, sex, and activity level (specific fields vary by tool).
- Calculate. Results appear instantly, with a clear number and context on what it means.
- Track and adjust. Recheck weekly or monthly as your weight or fitness level changes to see your progress.
That’s it. No account, no downloads, no data stored. Your numbers stay on your device.
Frequently Asked Questions
Are these fitness calculators really free?
Yes — every calculator is 100% free, with unlimited use and no sign-up required.
How accurate is the BMI calculator?
It uses the standard WHO formula (weight ÷ height²) and is accurate for most adults. BMI doesn’t account for muscle mass, so athletes may see skewed results — a body fat calculator gives a fuller picture.
Do the calculators work on mobile?
Absolutely. All tools are fully responsive and work on phones, tablets, and desktops.
What's the difference between BMR and TDEE?
BMR is the calories your body burns at complete rest. TDEE adds your activity level on top of BMR to give your total daily calorie burn — the number most people use for weight loss or gain planning.
Should I trust these calculators over a doctor's advice?
These tools give solid estimates for general planning, but they’re not a substitute for medical advice. For health conditions, pregnancy, or specific medical concerns, talk to a doctor or registered dietitian.