Somatotype.
A three-number description of any human body — how fat, how muscular, how linear — first laid out by William Sheldon in the 1940s, then turned into a measurable method by Heath and Carter in 1967. This is the field guide: thirteen distinct types, a cross-comparison library of athletes and populations, and a calculator that turns nine measurements into your own three numbers.
What a somatotype actually is.
A somatotype is three numbers in a row — for example, 3-5-2 — that together describe the *shape* of a body, independent of how big or small that body is. Two people of very different heights and weights can share the same somatotype if they are built the same way. Two people of the same height and weight can have very different somatotypes if one is lean and angular and the other is round and soft.
The Heath-Carter method, which is the version everyone uses today, derives those three numbers from nine measurements: height, weight, three skinfold thicknesses, two bone breadths, and two limb girths. It takes about fifteen minutes with a tape measure, a set of calipers, and a scale. The output is a single point on a triangular chart — the somatograph — that has been used in sports science, physical anthropology, and clinical research for nearly sixty years.
This section of the site is a port of an interactive somatotype application I built in 2022. The 2022 version had accounts, saved profiles, and a dashboard; this one is deliberately stateless — read the types, browse the library, take the test, screenshot your result. No signup, nothing stored.
The three components.
Every somatotype is a blend of these three. The first number is endomorphy, the second is mesomorphy, the third is ectomorphy.
Endomorphy
Relative fatness.
How much subcutaneous fat the body carries, measured from skinfolds at the triceps, subscapular, and supraspinale sites. High endomorphy gives a softer, rounder silhouette.
Mesomorphy
Relative musculoskeletal robustness.
How thick the skeleton and how developed the musculature, measured from bone breadths (humerus, femur) and limb girths (biceps, calf) corrected for fat. High mesomorphy gives the dense, square, athletic build.
Ectomorphy
Relative linearity.
How long and thin the body is for its weight, measured from the height-weight ratio. High ectomorphy gives the long, narrow, lightly-built silhouette of distance runners and high jumpers.
Four ways to explore.
Read the types, cross-reference athletes and populations, or calculate your own.
The 13 types
A directory of the thirteen distinct somatotype profiles, grouped into five categories — mesomorph, ectomorph, endomorph, hybrid, central. Each type gets its own page with portraits, a triangle graph, and a description.
Browse the types 02Comparison library
Tribes, sports, and occupations plotted against the three somatotype components. Filter and sort to see who shares your build — from rugby forwards to marathon runners to traditional populations studied in the original anthropometric literature.
Open the library 03Calculate yours
Enter the nine Heath-Carter measurements and see your own three numbers, your matched type, and where you land on the triangle. Stateless — nothing is saved. Screenshot the result if you want to keep it.
Take the test 04Heritage
The 2022 MERN-stack web application this section was ported from — and the 2019 single-page calculator that preceded it. Preserved as a screenshot gallery and a still-running prototype.
See the heritageWhere this came from.
This section is the third iteration. The first, in 2019, was a single HTML page with nine inputs and a canvas drawing the somatograph — built in the first weeks I was learning to code. The second, in 2022, was a full MERN-stack web application with accounts, dashboards, and a five-person contributor team. This one, in 2026, ports the four most useful pieces of that 2022 build into the AfitPilot marketing site as native Vue, stateless, bilingual, and meant to be read as much as used.
If you want the story of how each version came to be, both heritage pages are preserved below.