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Free Health & Fitness Calculators – BMR, Macros, Pace, Ovulation & More

Calculators for training, nutrition and well-being: work out your BMR and macros, how much protein you need and how many calories an activity burns, estimate your one-rep max, plan race paces and heart-rate zones, time your sleep around 90-minute cycles, and predict ovulation and periods.

13 tools

BMR CalculatorNEW

Calculate your basal metabolic rate with the Mifflin-St Jeor, Harris-Benedict and Katch-McArdle formulas, plus daily calories for every activity level.

Macro CalculatorNEW

Calculate your daily macros (protein, carbs and fat in grams) for fat loss, maintenance or muscle gain, with balanced, high-protein, low-carb and keto splits.

Protein Intake CalculatorNEW

Find how much protein you need per day based on your weight and goal: general health, endurance, building muscle, fat loss or healthy ageing.

Calories Burned CalculatorNEW

Estimate calories burned walking, running, cycling, swimming, weight training, yoga, sports and more, based on your weight and exercise time.

One Rep Max CalculatorNEW

Estimate your one-rep max from any set of reps, with a percentage chart for planning your training weights.

Pace CalculatorNEW

Calculate running pace, finish time or distance in kilometres or miles, with splits and race-time predictions for 5K, 10K, half marathon and marathon.

Heart Rate Zone CalculatorNEW

Calculate your maximum heart rate and five training zones from your age, with the Karvonen method if you know your resting heart rate.

Sleep CalculatorNEW

Find the best time to go to sleep or wake up based on 90-minute sleep cycles, so you wake up feeling refreshed instead of groggy.

Ovulation CalculatorNEW

Estimate your ovulation day and fertile window from your last period and cycle length, with the next three cycles and when to take a pregnancy test.

Period CalculatorNEW

Predict your next period and the following five from your last period date, cycle length and period length, and see which day of your cycle you're on.

Waist-to-Hip Ratio CalculatorNEW

Calculate your waist-to-hip ratio and waist-to-height ratio and see your health risk level based on WHO and common guidelines.

Lean Body Mass CalculatorNEW

Estimate your lean body mass (everything except fat) from your height and weight with three formulas, or from your body-fat percentage.

Steps to Calories CalculatorNEW

Convert steps to kilometres, miles and calories burned based on your height, weight and walking pace. How far is 10,000 steps?

Calculators for a healthier you

Whether you're training for a race, changing your diet, trying to sleep better or planning a family, these calculators turn established formulas into clear numbers. They're free, need no sign-up and run entirely in your browser, so your health data stays private.

Which calculator do I need?

I want to…Use
Know how many calories I burn at restBMR Calculator
Set protein, carb and fat targetsMacro Calculator
Know how much protein to eatProtein Intake Calculator
See what a workout burnsCalories Burned Calculator
Turn my steps into distance and caloriesSteps to Calories
Estimate my max liftOne Rep Max Calculator
Plan a race pacePace Calculator
Train by heart rateHeart Rate Zone Calculator
Wake up refreshedSleep Calculator
Find my fertile daysOvulation Calculator
Predict my next periodPeriod Calculator
Check my waist-to-hip ratioWaist-to-Hip Ratio Calculator
Estimate my lean body massLean Body Mass Calculator

More health calculators

In the calculators section: BMI, calorie (TDEE), body fat, ideal weight, water intake and pregnancy due date. For workouts, try the stopwatch and online timer.

About these estimates

Every calculator uses published, widely used formulas, such as Mifflin-St Jeor for metabolism, Riegel for race times and the Compendium of Physical Activities for exercise. They give good estimates for most people, but bodies vary.

For information only, not medical advice. Talk to a doctor, registered dietitian or qualified coach about your own health, diet or training, especially if you have a medical condition, are pregnant, or take medication.

Frequently asked questions

Are these calculators medical advice?

No. They give general estimates based on established formulas. Talk to a doctor, registered dietitian or qualified coach about your own health, diet or training.

Is my health information stored?

No. Every calculation runs in your browser, and nothing you enter is sent to a server or saved.

Can I use pounds and feet?

Yes. The calculators that need height or weight let you switch between metric (cm, kg) and imperial (ft, in, lb) units.