Health and Fitness

Health and Fitness calculators help you track body and wellness metrics — BMI and body composition, daily calorie needs, and a range of clinical indices. Popular tools include the BMI Calculator, TDEE Calculator, Reverse BMI (Height) Calculator, HOMA-IR Calculator, and Prostate Volume Calculator.

Enter your measurements for an instant estimate, or open the Trending tab to see what others are tracking this week. Every calculator is free and works on any device.

  • Reverse BMI: Height Calculator
    Calculate the ideal height for your target BMI with our Reverse BMI Calculator. Input your weight and desired BMI to find the corresponding height. Understand BMI ranges and categories easily with our visual guide. A useful tool for health and fitness planning.
  • Pounds and Ounces Calculator
    Add or subtract weights in pounds and ounces. Converts to total ounces, then normalizes back to pounds and ounces (16 oz = 1 lb).
  • Waist-to-Hip Ratio Calculator
    Calculate your waist-to-hip ratio (WHR) instantly. Divide waist by hip circumference to assess body fat distribution and health risk by gender.
  • Waist to Height Ratio Calculator
    Calculate your waist-to-height ratio (WHtR) instantly. Enter waist and height in cm or inches to gauge central fat and health risk. Free WHtR tool.
  • Due Date Calculator
    Calculate your due date accurately with this due date calculator. Input your last period and cycle length to determine your expected delivery date. Plan for your baby's arrival with precision.
  • Calorie Calculator
    Enter age, gender, height, weight, and activity to get daily calories. See your BMR, maintenance, and targets for weight loss or gain. Metric/imperial.
  • Grams of Protein Per Meal Calculator
    Convert grams of protein, carbohydrates and fat into calories. Calculate total kcal and macro percentage breakdown using the 4-4-9 Atwater factors.
  • BMI Calculator
    Calculate your BMI in seconds. Enter height and weight in metric or imperial units to get your body mass index and weight category instantly.
  • Height Calculator
    Predict a child's adult height from biological parents' heights using the mid-parental height formula. Returns predictions for both boys and girls in cm and ft+in with 95% confidence range.
  • TDEE Calculator
    Calculate your Total Daily Energy Expenditure (TDEE) with this TDEE Calculator. Input gender, age, height, weight, and activity level for accurate results. Supports Harris-Benedict and Mifflin-St Jeor formulas.
  • BMR Calculator
    Calculate your BMR from sex, birth year, height (cm), and weight (kg) using Harris–Benedict or Mifflin–St Jeor. Get calories/day at rest.
  • BRI Calculator
    Enter height and waist circumference to calculate your Body Roundness Index (BRI), see your score and category, and assess body shape risk.
  • Pace Converter
    Calculate and convert pace with this versatile Pace Converter. Transform time units between per mile, per kilometer, mph, km/h, m/min, m/s, yd/min, and yd/s for accurate running and speed analysis.
  • Period Calculator
    Predict your next period start date, see your current cycle day, and view a multi-month calendar marking predicted period days based on your last period and cycle length.
  • Modified Sgarbossa Criteria Calculator
    Calculate RMSSD heart rate variability from RR intervals. Also returns SDNN, mean RR interval and average heart rate from your beat-to-beat data.
  • TDEE to BMI Goal Weight Calculator
    Find your target body weight for any goal BMI. Enter your height and desired BMI to instantly calculate the weight (kg) you need to reach.
  • Fat Grams Per Pound Lost Calculator
    Find out how many calories you must burn to lose a pound of fat. Enter your goal weight loss and timeframe to get the total and daily calorie deficit.
  • Waist Circumference Percentile Calculator
    Check your abdominal-obesity health risk from waist circumference. Men >102cm/40in and women >88cm/35in flag high risk. Free, instant, cm or inches.
  • Odds Ratio Calculator
    Score the 21-item Beck Depression Inventory (BDI-II). Add each item (0-3) for a total of 0-63 and see your severity band: minimal, mild, moderate or severe.
  • Creatinine Clearance (IBW) Calculator
    Estimate creatinine clearance (CrCl) with the Cockcroft-Gault equation using age, weight, sex, and serum creatinine. Result in mL/min for renal dosing.
  • Epley 1RM Calculator
    Estimate your one-rep max (1RM) for bench press or any lift using the Epley and Brzycki formulas. Enter weight and reps to get instant results.
  • Mindful Walking Step Goal Calculator
    Track your daily step goal progress. Enter steps taken and your goal to see your completion percentage and steps remaining instantly.
  • Deep Breathing Heart Rate Zone Calculator
    Find your relaxation heart rate zone for deep breathing. Enter your age to get max heart rate and the calming 50–60% target range in bpm.
  • Dog Calories per Cup to Cups per Day Calculator
    Convert your dog's daily calorie needs (MER in kcal) to cups of food per day using the kcal-per-cup density on the bag. Free, instant feeding portion tool.

Frequently asked questions

What can I calculate with these health and fitness tools?

Body metrics such as BMI and body-fat estimates, energy needs like BMR and TDEE, target weights and heights, and clinical indices used in health assessments.

Is this medical advice?

No. These calculators are for information and education only and are not a diagnosis or treatment plan. Always consult a qualified healthcare professional about your health.

Are they free and private?

Yes — free, no sign-up, and your inputs stay in your browser; nothing you enter is logged or shared.

How accurate are the results?

They use established formulas and reference ranges, but individual factors such as age, muscle mass, and medical history affect real values — treat results as estimates.

Which health calculators are most popular?

The list is ordered by usage, most popular first; the Trending tab shows what's rising this week.

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