๐ช Fitness & Body Metrics
Free fitness calculators: BMI, body fat, lean mass, one-rep max, heart rate zones, healthy weight ranges and waist ratios.
Measure first, then train: BMI and waist ratios for a quick screen, body fat and lean mass for composition, one-rep max to anchor your lifting percentages, and heart-rate zones to pace cardio.
Each metric has known blind spots โ BMI cannot tell muscle from fat, formulas vary by population โ and the tool pages say so plainly, with the ranges they follow.
Army Body Fat Calculator
Calculate body fat percentage using the US Army AR 600-9 circumference method.
BMI Calculator
Enter your height and weight to calculate your Body Mass Index.
BMR Calculator
Calculate your Basal Metabolic Rate.
Body Fat Calculator
Estimate your body fat percentage.
Healthy Weight Calculator
Discover your healthy weight range based on your height. Enter your height to see the BMI-based healthy weight window (18.5โ24.9) and your ideal weight.
Heart Rate Calculator
Calculate your target heart rate zones for effective cardio training.
Ideal Weight Calculator
Find your healthy weight range.
Lean Body Mass Calculator
Estimate your lean body mass using multiple clinical formulas.
One Rep Max Calculator
Estimate your one-repetition maximum and training percentages for strength training.
Pace Calculator
Calculate your running pace, speed, and race finish times instantly.
TDEE Calculator
Calculate your daily calorie needs.
Waist-Hip Ratio Calculator
Calculate your waist-to-hip ratio and assess cardiovascular health risk.
Waist-to-Height Ratio Calculator
Calculate your Waist-to-Height Ratio (WHtR), a simple and powerful indicator of cardiometabolic health. Enter your waist circumference and height to see your ratio and risk category.
Frequently asked questions
Is BMI still useful?
As a population-level screen, yes; for individuals it misclassifies muscular and older bodies โ pair it with waist ratios and body fat.
How do I estimate body fat without a scanner?
The Navy tape method and skinfold formulas give workable estimates; each tool explains its accuracy limits.
What heart rate zone burns fat?
Lower zones burn a higher fat share, higher zones burn more total โ training across zones matters more than chasing one.