Body Type Calculator,
ectomorph, mesomorph, or endomorph.

Science guide

What is a body type and does it actually matter?

The concept of body types, formally called somatotypes, was developed by American psychologist William Herbert Sheldon in the 1940s. Sheldon proposed that human physiques could be described along three independent dimensions: endomorphy (roundness and softness), mesomorphy (muscularity and bone structure), and ectomorphy (linearity and leanness). Each dimension is scored on a scale of 1–7, producing a three-digit profile such as 1-5-3 (low endo, moderate meso, low ecto).

Sheldon’s original methodology had significant scientific problems (it was subjective and ideologically loaded), but the underlying morphological framework was later reformulated into a rigorous anthropometric system by Barbara Heath and J.E.L. Carter in the 1960s–70s. The Heath–Carter somatotype is now the standard method used in exercise science, sports medicine, and elite athletic research worldwide.

The three somatotype dimensions

How this calculator computes your scores

The full Heath–Carter method requires seven measurements: three skinfold thicknesses, two bone diameters, two limb circumferences, and height and weight. Because skinfold calipers and bone-width calipers are unavailable to most people, this calculator uses the following simplified but well-validated proxies:

Ectomorphy: from the Height-Weight Ratio (HWR)

The Heath–Carter ectomorphy component uses the Height-Weight Ratio:

• HWR ≥ 40.75: ectomorphy = 0.732 × HWR − 28.58
• 38.25 ≤ HWR < 40.75: ectomorphy = 0.463 × HWR − 17.63
• HWR < 38.25: ectomorphy ≈ 0.5 (minimal ectomorphy)

This formula is taken directly from Heath and Carter (1990) and is the only somatotype component that can be reliably computed without skinfold or bone-width measurements.

Endomorphy: from BMI as a proxy

In the full method, endomorphy is calculated from the sum of three skinfold measurements (tricep, subscapular, supraspinale), corrected for height. Without skinfolds, this calculator uses BMI as a proxy for relative adiposity: a person with BMI 18 has low endomorphy (≈ 1.5–2); a person with BMI 30+ has high endomorphy (≈ 6–7).

This is a reasonable approximation for the general population. It becomes less accurate for highly muscular athletes (high BMI from muscle mass, not fat); in those cases a professional body composition assessment is more appropriate.

Mesomorphy: from frame size

Mesomorphy in the full method is derived from bone widths (humerus and femur diameters) and limb circumferences corrected for skinfold thickness. As a practical proxy, this calculator uses frame size (determined from the wrist-to-height ratio) as the primary indicator of skeletal robustness.

Frame size from the wrist-to-height ratio:

• Men: r > 10.4 → small frame; 9.6–10.4 → medium; < 9.6 → large
• Women: r > 11.0 → small; 10.1–11.0 → medium; < 10.1 → large

A large-frame person has denser bone structure and typically scores higher on mesomorphy than a small-frame person at the same weight.

Body shape: from circumference ratios

If you provide chest/bust, waist, and hip measurements, the calculator also identifies your body shape using standard fashion-industry ratio rules:

• Hourglass: chest and hips roughly equal, waist more than 22 cm (≈ 9 in) smaller than both.
• Pear (Triangle): hips more than 9 cm (≈ 3.5 in) wider than the chest, with a defined waist.
• Inverted Triangle: chest more than 9 cm wider than the hips, common in male athletes and swimmers.
• Apple (Round): waist-to-hip ratio above 0.85 (women) or 0.90 (men), indicating central adiposity.
• Rectangle (Straight): all three measurements within roughly 10%, with minimal waist definition.

The waist-to-hip ratio and metabolic health

The waist-to-hip ratio (WHR) is one of the most predictive anthropometric measures of cardiometabolic risk, independent of overall BMI. The World Health Organization defines increased risk as WHR > 0.85 for women and > 0.90 for men; abdominal obesity (WHR > 0.90 for women, > 1.00 for men) correlates strongly with insulin resistance, type 2 diabetes, and cardiovascular disease.

Most people are a blend, not a pure type

The popular conception of body types as three mutually exclusive categories is an oversimplification. The Heath–Carter system scores all three dimensions independently: a 3-5-2 somatotype (moderate endo, high meso, low ecto) is not a pure mesomorph but a meso-dominant blend. Research on elite athletes shows that most are meso-dominant blends, with the secondary component reflecting their sport:

• Sprinters and throwers: endo-mesomorphs (3-6-2)
• Distance runners: ecto-mesomorphs (1-4-4)
• Gymnasts: ecto-mesomorphs (1.5-5-3)
• Powerlifters: endo-mesomorphs (4-7-1)
• Basketball players: meso-ectomorphs (2-4-4)

Can you change your body type?

Skeletal frame size and bone density, the mesomorphic substrate, are largely genetically determined and cannot be meaningfully changed through training. However, the adiposity (endomorphic) and muscular (mesomorphic) components can be shifted significantly through consistent resistance training and nutrition. A person who starts as an endo-dominant type can, over years of training, move toward a meso-dominant profile as they build muscle and reduce body fat.

The most productive framing is not “what type am I?” but “what does my current type tell me about how I should train and eat?” The training and nutrition recommendations in this calculator are calibrated to your dominant type to give you the highest-return starting point.

Limitations of this calculator

• BMI as an endomorphy proxy introduces error for muscular athletes (high BMI from muscle, not fat).
• No skinfold measurements means endomorphy estimates are less precise than the full Heath–Carter method.
• Mesomorphy estimation from frame size alone cannot capture individual variation in muscle mass.
• For research, clinical, or athletic assessment purposes, a trained anthropometrist using the full 7-measurement Heath–Carter protocol will produce more precise scores.

Disclaimer

This calculator is for educational and informational purposes only. It does not constitute medical or nutritional advice. Consult a qualified healthcare professional or registered dietitian before making significant changes to your diet or exercise programme.