Health and Fitness Calculators

These tools estimate the numbers that sit behind a health or training goal. Body measures such as BMI, body fat percentage, waist to height ratio and ideal weight put a single figure against published bands. Energy tools work out what your body burns at rest and across a day, then split a calorie target into protein, fat and carbohydrate. Training tools cover running pace, target heart rate zones, a one rep max estimate and daily water intake. Sleep cycles and a pregnancy due date round out the everyday health questions people search for.

Every one of these is a population estimate applied to an individual, which is the honest limit of the whole category. BMI cannot tell muscle from fat, so a heavily trained person reads as overweight on a scale that was never designed for them. Basal metabolic rate formulas carry a spread of several hundred calories between individuals of the same height, weight and age. A one rep max from a set of eight is an extrapolation, not a measurement. The bands are still useful as a starting point and a way to track change over time, which is what they are for.

Nothing here is medical advice and none of it replaces a clinician. If a result surprises you, or you are managing a condition, pregnant, or making a significant change to diet or training, take the number to a professional rather than acting on it alone.