FitCalc
Free health & fitness calculators that explain the numbers
51 free calculators for body composition, calories, nutrition, training and everyday health. Every one runs in your browser — nothing you type is uploaded, stored or tracked.
Body composition
BMI Calculator
Body Mass Index with healthy weight range.
Body Fat Calculator (Tape Method)
Estimate body fat % from a tape measure.
Body Fat from BMI (Deurenberg)
Estimate body fat from BMI and age.
Ideal Weight Calculator
Four classic formulas plus a healthy range.
Lean Body Mass Calculator
Lean mass and fat mass from weight and body fat.
Waist-to-Hip Ratio Calculator
WHR and your risk category.
Waist-to-Height Ratio Calculator
A better predictor than BMI for many.
Body Surface Area Calculator
BSA by Du Bois, Mosteller and Haycock.
FFMI Calculator (Fat-Free Mass Index)
Muscle mass relative to height, height-normalised.
Blood Pressure Category Calculator
Classify a reading and get your MAP.
Calories & weight
BMR Calculator
Basal metabolic rate at rest.
TDEE Calculator
Total daily energy expenditure.
Calorie Deficit Calculator
Deficit, expected loss and time to goal.
Weight Loss Timeline Calculator
Realistic date to reach your goal.
Weight Gain Calculator
Surplus calories to gain weight.
Calories Burned Calculator
Calories burned by activity (MET method).
Steps to Calories Calculator
Convert a step count into calories and distance.
Nutrition & alcohol
Macro Calculator
Protein, carbs and fat in grams.
Protein Intake Calculator
Daily protein target by goal.
Water Intake Calculator
How much water to drink daily.
Alcohol Calorie Calculator
Calories and units in drinks.
Blood Alcohol Content Calculator
Estimate BAC from drinks and time.
Glycemic Load Calculator
Blood-sugar impact of a serving.
Protein Per Meal Calculator
Daily and per-meal protein targets.
Keto Macro Calculator
Fat, protein and carbs for keto.
Fitness & training
One Rep Max Calculator
Estimate your 1RM from any set.
Target Heart Rate Calculator
Max HR and five training zones.
VO2 Max Calculator
Estimate aerobic capacity three ways.
Running Pace Calculator
Pace, speed and race predictions.
Pace & Split Calculator
Pace per km and mile, plus 5 km splits.
Race Time Predictor
Predict your time at other distances.
Heart Rate Reserve Calculator
Training zones by the Karvonen method.
Swimming Calories Calculator
Calories burned by stroke and time.
Cycling Calories Calculator
Calories burned riding, by intensity.
Walking Calories Calculator
Calories burned walking, by pace.
Treadmill Incline Calculator
Outdoor effort from speed and incline.
Health & timing
Sleep Cycle Calculator
Best bedtimes and wake times.
Pregnancy Due Date Calculator
Estimated due date and milestones.
Pregnancy Weight Gain Calculator
Recommended gain by week and BMI.
Ovulation Calculator
Fertile window and ovulation date.
Period Calculator
Predict your next six periods.
Age Calculator
Exact age in years, months and days.
Intermittent Fasting Calculator
Plan your eating and fasting window.
Sleep Debt Calculator
How much sleep you owe yourself.
Caffeine Half-Life Calculator
How much caffeine is left at bedtime.
A1C to eAG Calculator
Convert HbA1c to average glucose.
Pregnancy & family
Pregnancy Week Calculator
How far along you are, week by week.
Conception Date Calculator
Estimate when conception happened.
Child Height Predictor
Estimate a child's adult height.
Child & Teen BMI Calculator
BMI for children and teenagers.
Breastfeeding Calorie Calculator
Extra calories needed while nursing.
About FitCalc
Free health and fitness calculators for BMI, body fat, calories, macros, protein, water, one-rep max, heart-rate zones, running pace, race times, sleep, caffeine, pregnancy, child growth and more. Instant, private, no sign-up. Each calculator explains the formula behind the number, how to read the result, and where its limits lie — because a figure without context is not much use. Everything is calculated locally on your device, so sensitive numbers such as weight, age or health measurements never leave your browser.
FitCalc provides general information only and is not medical advice. Always consult a qualified health professional about your own situation.