2026-09-15 10 min

Somatotype Calculator

Run the full Heath-Carter somatotype: endomorphy from three skinfolds, mesomorphy from bone breadths and girths, ectomorphy from the ponderal index — plotted on a somatochart.

Calculator

Units

Weight

Morning scale weight

Height

Barefoot standing height

Triceps skinfold

Vertical fold, mid upper arm

Subscapular skinfold

Diagonal fold below shoulder blade

Supraspinale skinfold

Diagonal fold above hip bone

Calf skinfold

Vertical fold, inner calf

Humerus breadth

Elbow width, caliper

Femur breadth

Knee width, caliper

Flexed arm girth

Biceps flexed, max tape

Calf girth

Standing, max calf tape

Results update live as you type

Status:3.6 - 4.8 - 1.9Endomorphic mesomorphDominant: Mesomorph

Somatotype Results

Endomorphy3.6

Mesomorphy4.8

Ectomorphy1.9

Somatotype3.6-4.8-1.9

CategoryEndomorphic mesomorph

Component Breakdown

Component	Score	Driven by
Endomorphy (roundness)	3.6	Skinfold sum 37.0 mm, height-corrected
Mesomorphy (muscularity)	4.8	Bone breadths + corrected girths vs height
Ectomorphy (linearity)	1.9	Ponderal index 41.66
Plot (x, y)	-1.7, 4.1	Somatochart coordinates

Recommendations

▸Your somatotype is 3.6-4.8-1.9 (Endomorphic mesomorph) — quote all three numbers, never just the dominant
▸Mesomorph-dominant: respond to progressive overload quickly — run strength blocks with confidence and eat to support them
▸Re-measure quarterly: skinfolds move with body fat while breadths stay fixed, so the plot should migrate, not jump

Results

Normal

Somatotype

3.6-4.8-1.9

Endo-meso-ecto triplet in Carter order

Visualizations

Components (0-7.5)

3.6Endo

4.8Meso

1.9Ecto

Dominant vs Scale Max

Mesomorph4.8

Formula

Heath-Carter somatotyping quantifies physique in three continuous components: endomorphy (relative fatness) from a cubic skinfold regression, mesomorphy (musculoskeletal robustness) from bone breadths and fat-corrected girths against height, and ectomorphy (linearity) from the height-weight ratio with two branch points.

Somatotype = endo - meso - ecto (Heath-Carter)

Alternative Form

x = ecto - endo; y = 2 x meso - endo - ecto (somatochart)

Variables

Symbol	Name	Unit	Description
Endo	Endomorphy	0.1-7.5	Cubic regression on height-corrected skinfold sum
Meso	Mesomorphy	0.5-7.5	Breadth-girth regression minus height penalty
Ecto	Ectomorphy	0.1-7.5	Ponderal-index branches at 38.25 and 40.75
HWR	Ponderal index	ratio	Height / cube-root(weight)
x, y	Somatochart point	—	2D projection of the triplet

Explanation

Each component isolates one tissue logic: folds for fat, breadths-plus-lean-girths for muscle and bone, linearity for stretch. The somatochart projection then places every human physique on one shared map where training migrations become visible.

Derivation

X = (tri+sub+supra) x 170.18/H. Endo = -0.7182+0.1451X-0.00068X^2+0.0000014X^3. Meso = 0.858 humerus+0.601 femur+0.188(arm-tri/10)+0.161(calf-calfSkin/10)-0.131H+4.5. HWR = H/cbrt(W): >=40.75 ecto=0.732HWR-28.58; 38.25-40.75 ecto=0.463HWR-17.63; else 0.1.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Sum three skinfolds and height-correct the total.

X = (tri + sub + supra) x (170.18 / height)

Skinfold sum:37 mm

Intermediate: 37 x 170.18 / height = 37.0 scale-adjusted

Result: Height-corrected X computed from your inputs

Step 2

Run the cubic endomorphy regression.

Endo = -0.7182 + 0.1451X - 0.00068X^2 + 0.0000014X^3

X:height-corrected sum

Intermediate: Cubic curve maps folds to roundness, clamped 0.1-7.5

Result: Endomorphy = 3.6

Step 3

Correct girths for subcutaneous fat, then run mesomorphy.

Meso = 0.858H + 0.601F + 0.188Ac + 0.161Cc - 0.131Ht + 4.5

Corrected arm/calf:girth minus skinfold/10

Intermediate: Breadths plus lean girths, height-penalized

Result: Mesomorphy = 4.8

Step 4

Compute the ponderal index and branch ectomorphy.

HWR = height / cbrt(weight); branches at 38.25 / 40.75

HWR:41.66

Intermediate: Upper branch: 0.732 x HWR - 28.58

Result: Ectomorphy = 1.9

Step 5

Convert the triplet to somatochart coordinates.

x = ecto - endo; y = 2 x meso - endo - ecto

Triplet:3.6-4.8-1.9

Intermediate: 1.9 - 3.6 = -1.7; 2x4.8 - 3.6 - 1.9 = 4.1

Result: Plot (-1.7, 4.1)

Step 6

Name the category from dominant plus secondary.

All within 1.0 = Central; else dominant-secondary naming

Dominant:Mesomorph

Intermediate: Carter 13-category logic, simplified to the common names

Result: Endomorphic mesomorph

Final Answer

3.6-4.8-1.9

Worked Examples

See how the calculator works with different scenarios.

Scenario

A man 178 cm, 78 kg; folds 12/14/11/9 mm; breadths 7.0/9.5 cm; girths 33/38 cm.

Inputs

Height:178 cm

Weight:78 kg

Folds:12/14/11 mm

Girths:33/38 cm

Calculation

X = 37 x 170.18/178 = 35.37. Endo = -0.7182+5.1328-0.8509+0.0620 = 3.6. ArmC 31.8, calfC 37.1: meso = 6.006+5.7095+5.9784+5.9731-23.318+4.5 = 4.8. HWR = 178/4.2727 = 41.66: ecto = 30.493-28.58 = 1.9.

Result

3.6-4.8-1.9 — Endomorphic mesomorph

Interpretation

Muscle leads with softness second — classic off-season lifter: cut to reveal, do not bulk further.

Understanding Your Result

Your Result: Somatotype: 3.6-4.8-1.9

Typical range: Each component runs about 0.5-7.5 in practice; 2-5 covers most adults. Plot x spans roughly -6 to +6, y roughly -2 to +10 across populations.

What This Means

The complete Carter triplet with plot coordinates, ponderal index, skinfold sum, the named category, the dominant component, and training-relevant interpretation of each number.

Why It Matters

Single-label body typing (I am an endomorph) discards information. The triplet shows blends and magnitudes — the difference between 6.1-5.2-0.1 and 3.6-4.8-1.9 is the entire coaching plan.

Professional Interpretation

Track migrations, not snapshots: a falling endo with steady meso is recomposition; a rising meso at fixed folds is a successful bulk. Breadths never move — if they do, the caliper technique changed.

Why three skinfolds

Corrected girths

Recommendations

•Quote the triplet, never just the label
•Re-measure quarterly with the same measurer
•Skinfold skill dominates endo accuracy — get trained
•Compare against sport norms, not population averages
•Let meso guide training age expectations

Educational Content

Introduction

The Somatotype Calculator implements the Heath-Carter anthropometric method end to end. Enter the ten measurements and receive endomorphy, mesomorphy, ectomorphy, the somatochart point, and the category name.

Concept Explanation

Physique varies along three independent axes — fatness, robustness, linearity — and every body is a blend. Carter turned that philosophy into regressions any trained measurer can run with calipers and a tape.

Applications

▸Talent identification across sports

▸Tracking bulk, cut, and recomp phases

▸Comparing athletes within a squad

▸Research-grade physique description

▸Coaching communication with numbers

▸Long-term development monitoring

Benefits

•The actual published method, not a quiz
•Triplet captures blends single labels miss
•Somatochart visualizes your position
•Components map to training levers
•Metric and imperial supported

Limitations

•Needs calipers and breadths — not a home guess
•Measurer skill dominates skinfold error
•Describes shape, not fitness or health
•Single-day hydration shifts folds slightly

Best Practices

•Use a trained ISAK-style measurer
•Mark sites with a pen for repeatability
•Measure fasted, pre-training, same time
•Average duplicate skinfold pulls
•Keep the same caliper across assessments

Common Misconceptions

Myth: You are one pure type.

Truth: Almost nobody is. Most triplets blend within two points — the label is shorthand, the numbers are the truth.

Myth: Somatotype is genetic destiny.

Truth: Endo and ecto move substantially with diet and training; only the breadths are stubborn. Plots migrate year to year.

Myth: Online photo quizzes equal this.

Truth: Quizzes guess from silhouettes. Carter measures tissue with regressions validated against dissection-era data.

Practical Tips

•Learn the three-site skinfold routine before trusting endo
•Breadths need a caliper; estimates from photos fail
•Plot every assessment to watch your migration
•Compare within your sport, not against the general public
•Keep raw measurements, not just the triplet
•Same measurer, same caliper, same time of day

Common Mistakes

Pinching muscle with the skinfold

A thick fold with firm tissue underneath is muscle. Lift only skin and fat, let it settle, then read mid-pull.

Measuring girths cold vs pumped

A biceps pump adds a centimeter of theater. Standardize on rested protocol each time for honest trends.

Mixing calipers between sessions

Spring tension varies by brand and age. Trend breaks the day the hardware changes, so note the model.

Forgetting height correction on folds

Raw sums punish tall people. The 170.18/height factor exists precisely to stop that, so never skip it.

Quoting the label without numbers

Two endomorphic mesomorphs at 3.6-4.8-1.9 and 5.4-6.8-0.5 need opposite programs. Numbers first, always.

Assumptions

This calculator makes the following assumptions to provide estimates:

Trained measurer: Landmarks and pulls follow standard anthropometry protocol.

Millimeter folds: Skinfolds enter in mm in both unit systems.

Metric equations: Imperial lengths convert at 2.54 before regressions.

Adult bodies: Method validated on adult physiques, roughly 18+.

Clamped outputs: Components clamp to display ranges after rounding to 0.1.

Limitations

Be aware of these limitations when using this calculator:

Technique sensitivity: Skinfold error of 2-3 mm per site moves endo a full point.

Descriptive, not prescriptive: The triplet suggests emphases; it never contraindicates training.

No health diagnosis: Components correlate with risk factors but diagnose nothing.

Equipment floor: Without calipers and breadths this is estimation, not Carter.

Frequently Asked Questions

Answers to common questions about this calculator.

What is a somatotype?

A three-number physique rating — endomorphy (relative fatness), mesomorphy (musculoskeletal robustness), ectomorphy (linearity) — from the Heath-Carter anthropometric method, e.g. 3.6-4.8-1.9.

How is endomorphy calculated?

From a cubic regression on the height-corrected sum of triceps, subscapular, and supraspinale skinfolds: -0.7182 + 0.1451X - 0.00068X squared + 0.0000014X cubed.

How is mesomorphy calculated?

From humerus and femur breadths plus fat-corrected arm and calf girths, penalized by height: 0.858H + 0.601F + 0.188Ac + 0.161Cc - 0.131Ht + 4.5.

How is ectomorphy calculated?

From the ponderal index HWR = height / cube-root(weight): at or above 40.75 use 0.732HWR - 28.58; 38.25-40.75 use 0.463HWR - 17.63; below, 0.1.

What do somatochart x and y mean?

The 2D projection: x = ectomorphy minus endomorphy (linear left-right), y = twice mesomorphy minus the other two (muscularity upward). Up is muscular, left is round, right is linear.

What equipment do I need?

A scale, stadiometer, skinfold calipers, a small bone caliper for breadths, and a flexible tape — plus a measurer trained in landmarking.

How often should I re-test?

Quarterly. Skinfolds respond to body-composition change within weeks; breadths never move, which usefully audits technique.

Can somatotype predict sport success?

It correlates with sport demands — gymnasts cluster meso, marathoners ecto, throwers endo-meso — but skill, psychology, and training dominate selection.

Metric or imperial for somatotyping?

The equations run metric internally; this calculator converts imperial lengths at 2.54 and pounds at 2.20462. Skinfolds always enter in millimeters.

Why is my plot near the center?

Central (all components within about a point) is the most common adult result — a balanced, adaptable starting point, not a failed measurement.

Related Calculators

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Related Guides

Deepen your understanding with these educational resources.

Healthy Weight Fundamentals

Range math, waist checks, and when to look deeper.

Measuring Body Composition at Home

Tape protocol, scale timing, and trend tracking.

Activity and Calorie Basics

How NEAT, training, and diet move the numbers.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Endomorphy: Relative fatness component from skinfold regression.
Mesomorphy: Musculoskeletal robustness from breadths and corrected girths.
Ectomorphy: Linearity component from the ponderal index.
Ponderal index: Height divided by cube-root of weight (HWR).
Somatochart: 2D plot of x = ecto-endo against y = 2meso-endo-ecto.
Corrected girth: Girth minus its skinfold/10 — the lean circumference.
Circumference: Distance around a body site, measured with a flexible tape held level and snug without compression.
Screening tool: A simple test that flags who should look deeper — not a diagnosis of disease by itself.
Unit conversion: 1 inch equals exactly 2.54 centimeters; 1 pound equals 0.453592 kilograms.
Trend: The direction of repeated measurements over weeks, which matters more than any single reading.

Authoritative References

Trusted sources and standards referenced by this calculator.

WHO — Obesity and overweight fact sheet CDC — Assessing your weight and health risk NHLBI — Classification of overweight and obesity ACSM — Exercise and body composition resources Academy of Nutrition and Dietetics — Healthy weight guidance MedlinePlus — Weight management and health

Applicable Standards

WHO waist and waist-to-hip cut pointsACSM body composition assessment guidelines

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Page Information

Last Updated:

2026-09-15

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.