Enter your height, weight, waist, hip and optional shoulder tape measurements to compute your Waist-to-Height Ratio (Ashwell 0.50 boundary), Waist-to-Hip Ratio (WHO 2008 guidelines), BMI (with a lean-athlete muscle-mass check), and your closest Pelaris frame archetype.
Core Equation & Guard-Rail
WHtR = Waist ÷ Height (< 0.50) · WHR = Waist ÷ Hips · BMI = kg ÷ m²
A higher BMI with a Waist-to-Height Ratio below 0.50 can reflect muscle rather than central body fat. These adult cut-offs are for people aged 18 and over. The archetype is a quick tape-measure guess: the Body Scan reads your shape from photos and can land somewhere different. Tape ratios are general fitness estimates, never a medical assessment or diagnosis, and a doctor is the right person to ask about your health.
0.45
Below 0.50 (the usual guide)
0.83
Below WHO 0.9 cut-off
24.6
18.5 to 24.9 (WHO adult range)
For adults aged 18 and over. A general fitness estimate, not a medical assessment or diagnosis.
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WHtR = Waist ÷ Height (< 0.50) · WHR = Waist ÷ Hips · BMI = kg ÷ m²
A higher BMI with a Waist-to-Height Ratio below 0.50 can reflect muscle rather than central body fat. These adult cut-offs are for people aged 18 and over. The archetype is a quick tape-measure guess: the Body Scan reads your shape from photos and can land somewhere different. Tape ratios are general fitness estimates, never a medical assessment or diagnosis, and a doctor is the right person to ask about your health.
General fitness and training estimates only, labelled EST. Not medical advice or a clinical diagnosis.
Verified Literature
Waist-to-height ratio earns its place on your card, this review of 31 studies found it a sharper screening signal than BMI or waist alone.
Ashwell, M., Gunn, P. & Gibson, S. "Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis." Obesity Reviews, 2012;13(3):275-286. doi:10.1111/j.1467-789X.2011.00952.x
View the sourceYour waist-to-hip ratio is read against the World Health Organization's expert consultation, the global reference for what waist measurements genuinely tell us.
World Health Organization. Waist Circumference and Waist-Hip Ratio: Report of a WHO Expert Consultation, Geneva, 8-11 December 2008. Geneva: World Health Organization, 2011. ISBN 9789241501491, 39 pp.
View the sourceWe show BMI exactly as the World Health Organization defines it, using the same adult cut-offs public health uses worldwide.
World Health Organization. "Obesity and overweight" (fact sheet). Geneva: World Health Organization, last updated 8 December 2025.
View the sourceDeep-Dive Training Guides
Automatic Tracking & Adaptation
Inside Pelaris, you never need to punch numbers into a spreadsheet. Every logged set, run and check-in updates your estimates automatically and adapts next week’s sessions.
BMI divides total body weight by height squared and cannot tell muscle from fat. Ashwell, Gunn and Gibson’s review of 31 studies found waist-to-height ratio a better screening signal than BMI for cardiometabolic risk factors. Because it uses a waist measurement rather than body weight, it does not mistake muscle for fat in the same way BMI can.
Following the WHO 2008 protocol, measure your waist midway between the lowest rib and the top of the iliac crest (hip bone) at the end of a normal breath out, and measure your hips around the widest point of the buttocks with the tape level.
Pelaris groups shoulder, waist and hip proportions into six descriptive frame patterns (V-Taper, Linear, Block, Pear, Hourglass and Oval) to give your training context without ranking one frame above another.