Health & Fitness Calculators
Free calculators for body metrics, nutrition planning, and fitness tracking. Whether you are figuring out your daily calorie needs, protein targets, or training zones, each tool shows the underlying formula and a worked example — not just a black-box result.
Featured Calculators
- BMR calculator using the Mifflin-St Jeor equation
Calculate your Basal Metabolic Rate with the Mifflin-St Jeor formula. Shows the full equation for men and women with a worked example.
- TDEE calculator — Total Daily Energy Expenditure with activity level
Multiply your BMR by an activity factor to find how many calories you actually burn each day.
- calorie deficit calculator for weight loss
Set a weekly weight-loss target and find the daily calorie deficit required to reach it.
- daily protein needs calculator by body weight
Estimate your daily protein requirement based on body weight, activity level, and training goal.
- lean body mass calculator from weight and body fat percentage
Calculate lean body mass from total weight and body fat percentage using multiple validated formulas.
- BMI calculator — Body Mass Index by height and weight
Compute body mass index in metric or US units with category classification.
All Health & Fitness Tools
- Body Fat Percentage Calculator
Estimate body fat percentage using the U.S. Navy circumference method.
- Ideal Weight Calculator
Estimate ideal body weight range from height using BMI-based targets.
- Waist-to-Hip Ratio Calculator
Compute waist-to-hip ratio and basic cardiometabolic risk band.
- One Rep Max Calculator
Estimate 1RM from lifted weight and repetitions using the Epley formula.
- Pace Calculator
Calculate running pace from distance and finish time.
- Heart Rate Zones Calculator
Calculate training zones using the Karvonen method.
- Calories Burned Calculator
Estimate calories burned from activity MET, duration, and body weight.
- Steps to Distance Calculator
Convert step count to walking distance based on stride length.
- Swimming Pace Calculator
Calculate swim pace per 100m from total distance and time.
- Cycling Power Calculator
Estimate required cycling power from speed, rider mass, and road grade.
- Macro Split Calculator
Convert calorie targets into grams of protein, carbs, and fat using macro ratios.
- Water Intake Calculator
Estimate daily hydration target from weight, activity, and climate.
- Intermittent Fasting Calculator
Determine fasting and eating windows from your selected protocol and start time.
- Due Date Calculator
Estimate pregnancy due date based on first day of the last menstrual period.
- Ovulation Calculator
Estimate ovulation and fertile window from cycle length and last period date.
- Medication Dosage Calculator
Reference dosage range from weight and mg/kg prescription guidance.
- Blood Alcohol Calculator
Estimate BAC from drinks consumed, body weight, sex, and elapsed time.
- Kidney Function (eGFR) Calculator
Estimate eGFR using CKD-EPI 2021 creatinine equation.
- VO2 Max Estimator
Estimate VO2 max from resting and maximum heart rate.
- Running Race Predictor
Predict race times at common distances using a known result and Riegel scaling.
- Target Heart Rate Workout Planner
Compute target training zone and total time in zone for a planned workout.
- Menstrual Cycle Tracker
Estimate next period and fertile windows using min/max cycle lengths for irregular cycles.
- Medication Schedule Checker
Check timing overlap risk between two repeating medication schedules.