Health Calc

Free BMR calculator using the Mifflin-St Jeor equation. Find out how many calories your body burns at rest.

Reach for BMR when you're building a nutrition plan from scratch and need a true starting point before adding activity on top.

Free TDEE calculator. Combine your BMR with your activity level to find your total daily calorie burn.

This is the number to calculate before starting almost any diet or training plan, whether the goal is losing, gaining, or simply holding steady.

Free calorie calculator. Get a daily calorie target for losing, maintaining, or gaining weight based on your stats and goal.

Use this once you know you want to lose, gain, or maintain weight and need an actual daily number to aim for, rather than guessing.

Free macro calculator. Turn a daily calorie target into grams of protein, carbs, and fat for balanced, high-protein, low-carb, or keto eating.

Turn to this after you've settled on a calorie target and want to structure what that food actually looks like, especially if you're trying a specific eating style like higher protein for muscle retention, or lower carb for personal preference.

Free water intake calculator. Estimate your daily fluid needs based on body weight and exercise.

Check this when you're setting a hydration habit, starting a new exercise routine, or moving somewhere hotter or more humid than you're used to.

Free calories burned calculator. Estimate energy burned during exercise based on activity type, body weight, and duration.

Use this to get a rough sense of the calorie cost of a workout, particularly useful if you're tracking intake and want to understand how much room a training session buys you.

Free BMI calculator. Enter your height and weight to find your Body Mass Index and see which category it falls in.

Use BMI as a quick first check-in on your weight relative to your height, or to track how that ratio shifts over months or years.

Free body fat calculator using the U.S. Navy circumference method. Estimate body fat percentage from tape measurements.

Use this alongside the scale, not instead of it, especially if your weight isn't moving but your body seems to be changing shape — a common experience when building muscle while losing fat.

Free ideal weight calculator using the Devine formula. Get a reference body weight range based on height and sex.

Treat this as a rough anchor point for a conversation with a trainer or doctor, or as one input among several when setting a long-term weight goal — not a number to chase exactly.

Free Army body fat calculator using the official tape-measure method. Check your estimated body fat percentage against military standards for your age and sex.

Use this ahead of an official body composition assessment to get a sense of where you stand before it counts, or periodically during a training cycle if you're working toward a specific standard.

Free lean body mass calculator using the Boer formula. Estimate the weight of everything in your body that isn't fat.

Use this alongside a body fat percentage reading to see the fuller picture of what your weight is made of, especially useful when tracking a body recomposition where the scale isn't moving much but your proportions are changing.

Free healthy weight calculator. Find the weight range considered healthy for your height, based on standard BMI cutoffs.

Use this instead of chasing one exact number, especially if you find a single ideal weight figure demotivating or overly rigid.

Free heart rate zone calculator. Find your estimated max heart rate and training zones for warm-up, fat burn, cardio, and max effort.

Use this to structure training intensity deliberately — keeping easy runs genuinely easy in Zone 2, and making sure hard interval sessions actually reach Zone 4 or 5 rather than sitting in an unproductive middle ground.

Free running pace calculator. Enter your distance and finish time to find your pace per kilometre or mile, and your average speed.

Use this while planning race strategy — figuring out what pace a goal finish time actually requires, or converting a training pace between kilometres and miles when following a plan written in the other unit.

Free one rep max calculator. Estimate your one-repetition max for any lift from a lighter, higher-rep set.

Use this instead of actually testing a true one-rep max, which carries real injury risk without a spotter and proper technique.

Free target heart rate calculator using the Karvonen method. Get personalised training zones that account for your resting heart rate.

Use this instead of a simple age-based heart rate zone if you know your resting heart rate, since it accounts for your current fitness level rather than just your age.

Free sleep calculator. Find the best bedtime or wake-up time based on 90-minute sleep cycles.

Use this when you have a fixed wake-up time and want to work backward to a bedtime that ends a sleep cycle rather than interrupting one, or the reverse when you know what time you're getting into bed tonight.

Free ovulation calculator. Estimate your ovulation day, fertile window, and next period based on your cycle length.

Use this if you're trying to understand your cycle better, whether you're trying to conceive, tracking symptoms, or just want more predictability around your period.