Free health & fitness tools

Free Health & Fitness Calculators

Fast, accurate tools for BMI, daily calories, macros, body fat, hydration and more — each with tailored what-to-eat and what-to-do tips after your result. Works in metric and imperial, with no sign-up.

Try the BMI calculator → Calculate your calories

30 free calculators Metric & imperial Tips after every result

Body composition

See where your weight, muscle and body fat stand.

BMI Calculator Popular See whether your weight sits in a healthy range for your height. Navy Body Fat Calculator Estimate body fat with the U.S. Navy tape-measure method — neck, waist and height. FFMI Calculator Gauge your muscle mass relative to height (fat-free mass index). Lean Body Mass Calculator Estimate your lean mass and fat mass. Waist-to-Hip Ratio Calculator Your WHR and health-risk category. Waist-to-Height Ratio Calculator Is your waist under half your height? Check your NICE risk band. Ideal Weight Calculator A healthy-weight range for your height using the Devine formula. BSA Calculator (Body Surface Area) Your BSA in m² by Mosteller, Du Bois and more.

Calories & energy

Find your burn, deficit and daily calorie targets.

Calorie & TDEE Calculator Popular Estimate the calories you burn per day and targets to lose or gain. BMR Calculator The calories your body burns at complete rest. Calories Burned Calculator Calories burned by activity, weight and time. Steps to Calories Calculator Convert steps to calories burned — plus a steps-to-calories chart and the reverse. Calorie Deficit Calculator The daily deficit and intake for your target rate. Weight Loss Timeline Calculator See how long to reach your goal weight, with a target date.

Nutrition

Dial in macros, protein, carbs, fasting and hydration.

Macro Calculator Popular Split a daily calorie target into protein, carbs and fat. Protein Calculator Your daily protein target for your weight and goal. Carbohydrate Intake Calculator Daily carb grams for your calories and goal. Intermittent Fasting Calculator Free fasting calculator — turn a method into your eating and fasting windows. Water Intake Calculator How much water to drink a day, from your body weight and exercise.

Fitness & performance

Track strength, running and heart-rate training.

One-Rep Max Calculator Estimate your 1RM and a training-percentage table. Running Pace Calculator Get pace per km and mile plus average speed from a time. Race Time Predictor Predict finish times at other distances from a recent race. Target Heart Rate Calculator Your max heart rate and five training zones by age.

Everyday health

Sleep timing and life-stage tools.

Sleep Calculator Best bedtimes and wake-up times by 90-minute sleep cycles. Pregnancy Due Date Calculator Due date from your last period, conception or IVF transfer.

Guides

Plain-language answers that pair with the tools.

How Many Calories Should You Eat to Lose Weight? Find your maintenance calories, set a safe deficit, and turn it into a daily target. Read the guide → How Much Water Should You Drink a Day? The real answer beyond '8 glasses' — how much fluid you actually need and why. Read the guide → What Is a Healthy BMI? Chart, Ranges and Limits The healthy BMI range, the full category chart, and where BMI falls short. Read the guide →

All guides →

Health calculators you can actually trust

Healthy Calculator Hub brings the most-used health and fitness calculators together in one fast, clean place. Each tool uses a recognised formula — Mifflin-St Jeor for calories, the U.S. Navy method for body fat, Epley and Brzycki for one-rep max — and shows both a clear number and a plain-language interpretation so you know what the result actually means.

Whether you're setting a calorie target, checking whether your weight sits in a healthy range, dialling in your macros, or planning a race pace, you'll get an instant answer without adverts burying the tool or a sign-up wall in the way. Start with a BMI check, estimate your daily calories, then split them with the macro calculator.

Estimates for education, not medical advice

Every calculator here provides general estimates for educational purposes only. Formulas are built for populations, so individual results vary with age, genetics, health conditions, and measurement accuracy. Nothing on this site is a substitute for professional care — please consult a qualified healthcare provider before making decisions about your health, diet, or exercise. You can read more on our about page.