Body & Weight Calculators
Evaluate your body composition, skeletal muscle mass, and central adiposity using validated clinical equations from the World Health Organization, UK NICE, and the US Navy.
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Clinically Validated
Peer-reviewed medical models
Calculators in this Category (9)
Select a tool to compute customized results with instantaneous formula execution.
BMI Calculator
Calculate your Body Mass Index in metric or imperial, with CDC youth LMS percentiles and Asian cut-offs.
BMR Calculator
Calculate your Basal Metabolic Rate using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle.
TDEE Calculator
Estimate your Total Daily Energy Expenditure and discover your true maintenance calories.
Ideal Weight Calculator
Find your healthy body weight range based on BMI, Devine, Robinson, Miller, and Hamwi formulas.
Body Fat Calculator
Estimate your body fat percentage using the US Navy tape method or Deurenberg BMI equation.
Lean Body Mass Calculator
Calculate your lean body mass from height and weight using Boer, James, and Hume formulas or body fat %.
Waist-to-Height Ratio Calculator
Keep your waist to less than half your height. Check your WHtR and health risk category instantly.
Waist-to-Hip Ratio Calculator
Calculate your waist-to-hip ratio and check your cardiovascular risk against official WHO cut-offs.
Fat-Free Mass Calculator
Calculate your fat-free mass and FFMI from weight, height and body fat %. See your normalized FFMI.
Beyond Single-Metric Body Assessment
Body mass index (BMI) provides a helpful population-level screening metric, but does not differentiate between dense skeletal muscle and adipose fat. Combining BMI with Lean Body Mass (Boer formula) and Waist-to-Height Ratio offers a significantly clearer clinical picture of individual metabolic health.
According to UK NICE guideline NG246, maintaining a waist circumference less than half your standing height (WHtR < 0.50) strongly correlates with lower lifetime risk of type 2 diabetes and hypertension.
Frequently Asked Questions
Which body composition calculator should I start with?
We recommend checking both your BMI and Waist-to-Height Ratio (WHtR) together. WHtR identifies visceral abdominal fat that BMI may overlook in lean or muscular individuals.
How accurate is the US Navy body fat formula?
When measurements are taken carefully with a flexible tape, the US Navy formula typically correlates within 3 to 4 percentage points of dual-energy X-ray absorptiometry (DEXA) scans.