All Health Calculators

13 free percentile calculators in 4 categories. Every tool uses NHANES data or a peer-reviewed normative study. Private, no signup.

Strength & Upper Body

Grip strength, lean body mass, arm circumference, and strength-to-weight ratios.

Grip Strength How your hand strength compares to US adults your age. A powerful longevity predictor.

Lean Body Mass Estimate your muscle mass and see how it ranks against the US population.

Arm Circumference Mid-upper arm circumference norms by age and sex from NHANES data.

Strength-to-Weight Ratio How your lifts compare to bodyweight-based strength standards.

Body Girth & Adiposity

Waist, hip, WHR, and BMI. The measurements clinicians use most for cardiometabolic screening.

Waist Circumference Abdominal fat measurement with WHO risk thresholds. Stronger predictor than BMI.

Hip Circumference Hip measurement norms by age and sex from the NHANES survey.

Waist-to-Hip Ratio Body fat distribution — apple vs pear shape — and associated health risks.

BMI Percentile See where your BMI falls compared to US adults matched for age and sex.

Vital Signs & Cardiac

Resting heart rate, walking speed, and gait speed norms. Strong markers of cardiovascular fitness.

Resting Heart Rate Lower is generally better. Compare your RHR to age and sex norms.

Walking Speed A simple test strongly linked to longevity and functional independence.

Gait Speed Norms Clinical reference values and fall risk assessment for adults 65+.

Body Shape Indices

Body Roundness Index and Waist-to-Height Ratio. Newer metrics that model fat distribution.

Body Roundness Index JAMA 2024-validated body shape metric. Models your body as an ellipse.

Waist-to-Height Ratio Simple rule: your waist should be less than half your height.