Free body type calculator
Find your body type in two seconds. Enter your height and weight and the calculator works out your BMI, then maps it to a simplified body type — ectomorph (lean), mesomorph (athletic), or endomorph (rounded) — with a full somatotype breakdown and training-and-nutrition guidance, updated live, as you type.
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Body shape classifications are based on measurements only and do not reflect health status or body composition.
Results are estimates. Consult a professional.
What is your body type?
Your body type — sometimes called your somatotype — is a label for your overall build: how lean, muscular, or rounded your frame tends to be. The classic system sorts people into three types: ectomorph (naturally lean and slim), mesomorph (naturally muscular and athletic), and endomorph (naturally softer and rounder). Most people are not a pure type; they are a blend that leans toward one of the three. This body type calculator gives you a quick read by taking your height and weight, working out your BMI, and matching that to the body type its category most resembles.
The three body types: ectomorph, mesomorph, endomorph
The three-type model comes from psychologist William Sheldon, who in the 1940s described three components of physique he called somatotypes. The original theory linked build to personality and has been thoroughly discredited on that front — but the three physical descriptions survived in fitness culture as a handy shorthand for body build. Here is what each type means in plain terms, and how the common advice differs.
| Body type | Typical traits | How to train | How to eat |
|---|---|---|---|
| Ectomorph | Lean and slim, narrow shoulders and hips, long limbs, finds it hard to gain weight or muscle. | Focus on heavy compound lifts and lower-rep strength work; keep cardio modest so you don't burn off hard-won gains. | Eat in a calorie surplus with plenty of carbohydrates and protein; frequent meals help if appetite is the limiter. |
| Mesomorph | Naturally muscular and athletic, broad shoulders, gains muscle readily and can lean out without much trouble. | Responds well to almost any program — mix strength and hypertrophy work; easy to recomposition. | Eat at or near maintenance with balanced macros; adjust up or down depending on whether the goal is muscle or leanness. |
| Endomorph | Softer, rounder build, wider waist and hips, gains weight (and muscle) easily but loses fat more slowly. | Combine resistance training with regular cardio to manage body fat; higher training volume tends to suit. | Eat in a modest calorie deficit when fat loss is the goal, with higher protein and more careful carb timing. |
Common fitness-culture descriptions of the three Sheldon somatotypes. Treat these as starting points, not rules — see the science caveat below.
What determines your body type?
A few things combine to set your build, and only some of them are within your control.
- Bone structure (genetics). Shoulder width, frame size, and limb length are largely inherited and fixed once you finish growing. This is the part that makes someone 'naturally' lean or broad.
- Muscle and fat distribution. How readily you build muscle and where you store fat is partly genetic — but it is also the part you can move most with training and nutrition.
- Hormones and metabolism. Differences in metabolic rate, sex hormones, and insulin sensitivity influence how easily you gain or lose weight, which shapes the type you express.
- Lifestyle. Years of training, diet, sleep, and activity layer muscle and fat over your inherited frame — which is why a lean teenager and the same person decades later can read as different types.
How this body type calculator works
A full somatotype assessment uses tape and caliper measurements — skinfolds, bone breadths, and limb girths — to rate all three components on a numeric scale. That is more than a quick web tool can do. Instead, this calculator gives you a fast approximation: it takes your height and weight, computes your BMI, and maps the resulting category to the body type it most resembles. It is a simplified proxy, not a measured somatotype.
| BMI category | BMI range | Maps to body type |
|---|---|---|
| Underweight | below 18.5 | Ectomorph (lean / slim build) |
| Normal weight | 18.5 – 24.9 | Mesomorph (athletic / balanced build) |
| Overweight | 25.0 – 29.9 | Endomorph-leaning (softer / rounder build) |
| Obese | 30.0 and above | Endomorph (rounded build) |
How this tool maps your WHO BMI category to a simplified body type. BMI cannot see muscle vs. fat, so the mapping is a rough guide — a muscular person in the overweight BMI band is not an endomorph.
A worked example using the body type calculator
Daniel is 1.78 m tall and weighs 68 kg. He wants a quick read on his body type. Here is exactly what the calculator does.
- Square the height. 1.78 × 1.78 = 3.17 m².
- Divide weight by that figure. 68 ÷ 3.17 = 21.5 — Daniel's BMI.
- Match the BMI to a category. 21.5 sits inside the 18.5–24.9 normal-weight band.
- Map the category to a body type. The normal-weight band maps to the mesomorph (athletic, balanced) body type.
Now see why composition matters. Suppose Daniel instead weighed 88 kg at the same height — a BMI of 27.8, in the overweight band, which the tool maps toward endomorph. But if that extra weight were mostly muscle from years of lifting, his true build is closer to mesomorph than endomorph. That gap is exactly why this result is a starting point, not the last word — pair it with a body fat reading when composition is the real question.
Training and nutrition by body type
The practical appeal of body types is that they hint at a useful default for training and eating. These are sensible starting points — but the honest version is that the same principles apply to everyone, just dialled differently. Progressive resistance training builds muscle for all three types; energy balance decides fat gain or loss for all three. Body type mostly tells you which lever to lean on first.
- If you read as an ectomorph — the usual struggle is gaining size. Eat enough to be in a surplus, prioritise compound strength work, and keep extra cardio modest so you're not burning off the calories you're trying to add.
- If you read as a mesomorph — you tend to respond fast to almost anything. Pick a goal (build or lean out), eat near maintenance, and progress your lifts; recomposition comes relatively easily.
- If you read as an endomorph — the usual goal is managing body fat while building muscle. Combine resistance training with regular cardio, lean on protein, and run a modest, sustainable calorie deficit when fat loss is the aim.
How to tell which body type you are
Beyond the BMI shortcut this calculator uses, the everyday way people identify their type is by looking at their frame and asking a few honest questions about how their body responds. No single answer is decisive — you're looking for the type your answers lean toward.
- Look at your bone structure. Narrow shoulders, fine wrists, and long limbs point toward ectomorph; broad shoulders and a sturdy frame toward mesomorph; a wider, rounder build toward endomorph. A quick proxy some calculators use is the wrist-to-height ratio — a thinner wrist for your height suggests a lighter frame.
- Ask how easily you gain weight. If you struggle to put on any weight, you lean ectomorph; if you gain weight (and muscle) easily, you lean endomorph; if you sit comfortably in between, mesomorph.
- Ask how easily you build muscle. Fast, visible response to training points to mesomorph; a slow, hard grind points to ectomorph; easy muscle gain alongside easy fat gain points to endomorph.
- Accept that you're probably a blend. Pure types are rare. Most people are a mix — ecto-meso, meso-endo — and the goal is to spot your dominant tendency, not to force yourself into one box.
Can you change your body type?
Partly — and this is where the framework is most often misunderstood. Your underlying bone structure is set by your genes and doesn't change once you've finished growing, so you can't turn a naturally narrow-framed ectomorph into a broad-framed mesomorph at the skeleton level. That part is fixed.
What you can change is the muscle and fat layered over that frame — which is most of what people mean when they talk about their body type. With consistent resistance training and the right nutrition, a lean ectomorph can build real muscle and start to look more mesomorphic, and an endomorph can lean out considerably. People rarely change their dominant type outright, but they routinely shift how they express it. Body type sets your starting point and your tendencies, not a ceiling you can't move past.
Body types: science vs. pseudoscience
It's worth being clear about what the body-type framework is and isn't. Sheldon's original somatotype theory tried to link body build to personality and temperament — claiming, for instance, that lean people were more intellectual. That part has been firmly rejected by modern psychology; there is no credible evidence that your build predicts your character.
What survives is the looser, descriptive use: ectomorph, mesomorph, and endomorph as a quick shorthand for lean, muscular, and rounded builds. Used that way it's a reasonable rule of thumb. But the popular idea that each type needs a rigidly different diet or training style is largely overstated. People also rarely fit one pure type, builds change with training and age, and there are no strict cut-offs separating the categories.
Body type vs. body shape — what's the difference?
Body type and body shape sound alike but answer different questions. Body type (this tool) describes your overall build — how lean, muscular, or rounded you are — using the ectomorph / mesomorph / endomorph framework, inferred here from your BMI. Body shape describes the outline your proportions create — the relationship between your bust, waist, and hips — sorting a figure into Hourglass, Pear, Apple, or Rectangle.
| Body type | Body shape | |
|---|---|---|
| Question it answers | How lean / muscular / rounded is your build? | What outline do your proportions create? |
| Categories | Ectomorph, Mesomorph, Endomorph | Hourglass, Pear, Apple, Rectangle |
| Inputs used | Height and weight (BMI proxy) | Bust, waist, and hip measurements |
| Best for | Training and nutrition framing | Styling, fit, and proportion |
Two people can share a body type but have completely different shapes, and vice versa. If you want your bust/waist/hip outline, use the body shape calculator. For the weight-for-height number this tool is built on, see the BMI calculator; and when body composition is the real question — muscle vs. fat — the body fat percentage calculator and FFMI calculator are the right tools.
Data sources and methodology
The three-type framework is the somatotype model first described by William H. Sheldon in the 1940s and later refined into the measurement-based Heath-Carter method. The personality claims in Sheldon's original work are discredited; only the physical descriptions are used here. This calculator does not perform a Heath-Carter assessment — it computes BMI from your height and weight using the WHO adult classification and maps the resulting category to a simplified body type, so the result is an approximation, not a measured somatotype.
BMI formula and adult category bands: World Health Organization adult BMI classification (underweight <18.5, normal 18.5–24.9, overweight 25–29.9, obese ≥30).Frequently asked questions about the free body type calculator
About this body type calculator
This body type calculator runs entirely in your browser. The height and weight you enter never leave your device — nothing is sent to a server, logged, or shared. It computes your BMI, maps the WHO category to a simplified body type, and updates instantly as you type.
Calculators Cloud offers 400+ free tools with no sign-up. The whole Health calculators shelf includes the body shape, BMI, Body fat %, and FFMI tools alongside this one. Or browse the full calculator directory.