Body Type Calculator — Free Online Somatotype Tool

How to Use the Body Type Calculator

1. Select your unit system: Choose Metric (centimeters) or Imperial (inches) using the toggle at the top. All fields adjust to match your preference.
2. Enter your height: Input your standing height. In Metric mode, enter centimeters directly. In Imperial mode, enter feet and inches separately. Stand barefoot and straight for the most accurate measurement.
3. Measure your wrist circumference: Wrap a flexible tape measure around your dominant wrist, just above the wrist bone (the bony protrusion on the outside of your wrist). The tape should be snug against the skin but not compressing. Record the measurement and enter it in the calculator. This measurement reflects your skeletal frame size, as the wrist has minimal muscle and fat.
4. Review your results: The calculator instantly displays your body type (ectomorph, mesomorph, or endomorph), the height-to-wrist ratio used for classification, your frame size (small, medium, or large), and typical characteristics associated with your body type.

Remember that most people are a blend of body types. Use this result as a general guideline for understanding your natural tendencies, not as a rigid classification.

Body Type Formula and Classification Method

Classification Thresholds

• Ratio above 10.4 → Ectomorph (Small Frame): Indicates a lean, slender skeletal structure. People with this ratio typically have narrow shoulders and hips, long limbs relative to torso, and a naturally fast metabolism.
• Ratio 9.6 to 10.4 → Mesomorph (Medium Frame): Indicates a medium skeletal structure. People with this ratio tend toward an athletic build with balanced proportions and a moderate metabolism.
• Ratio below 9.6 → Endomorph (Large Frame): Indicates a larger, wider skeletal structure. People with this ratio typically have broader shoulders and hips, a naturally stockier build, and a tendency to store energy more efficiently.

Step-by-Step Calculation Example

For a person who is 175 cm tall with a wrist circumference of 17.5 cm:

1. Divide height by wrist circumference: 175 / 17.5 = 10.0
2. Compare to thresholds: 10.0 falls between 9.6 and 10.4
3. Classification: Mesomorph (Medium Frame)

This person has a medium skeletal frame, suggesting an athletic tendency. A ratio of 10.0 is right in the middle of the mesomorph range, indicating a well-balanced frame size.

Practical Examples

Example 1: Kevin Planning His Training Program

Kevin is a 25-year-old who has struggled to gain muscle despite regular gym attendance. He is 182 cm tall with a wrist circumference of 16.5 cm:

• Ratio: 182 / 16.5 = 11.0
• Classification: Ectomorph (Small Frame)
• Frame Size: Small

Kevin's ectomorph classification explains his difficulty gaining weight. His trainer recommends focusing on compound exercises (squats, deadlifts, bench press) with progressive overload, reducing cardio volume, and increasing caloric intake by 500 calories per day with emphasis on protein and complex carbohydrates.

Example 2: Sarah Choosing the Right Sport

Sarah is a 17-year-old exploring different sports. She is 168 cm tall with a wrist circumference of 15.5 cm:

• Ratio: 168 / 15.5 = 10.8
• Classification: Ectomorph (Small Frame)
• Frame Size: Small

Sarah's ectomorph build with a small frame suggests she may excel in sports that favor lean, long-limbed physiques such as distance running, swimming, or cycling. However, body type is just one factor among many, including skill, motivation, and enjoyment, that should guide sport selection.

Example 3: Marco Understanding His Natural Build

Marco is a 40-year-old who has always had a stockier build. He is 170 cm tall with a wrist circumference of 18.5 cm:

• Ratio: 170 / 18.5 = 9.2
• Classification: Endomorph (Large Frame)
• Frame Size: Large

Marco's endomorph classification reflects his naturally wider build and larger bone structure. Understanding this helps him set realistic physique goals. His trainer designs a program combining strength training to build muscle with cardiovascular exercise to support metabolic health, focusing on sustainable habits rather than chasing an ectomorph physique.

Body Type Classification Reference Table

Tips and Complete Guide to Body Type Understanding

Body Type Is a Starting Point, Not a Limitation

Understanding your body type can help set realistic expectations and tailor your fitness approach, but it should never be treated as a limitation. Countless examples exist of individuals who have dramatically transformed their physiques regardless of their natural body type. An ectomorph can build impressive muscle mass with the right training and nutrition strategy. An endomorph can achieve a lean, athletic physique through consistent exercise and dietary management. Your body type influences your starting point and the relative ease of certain changes, but it does not determine your ceiling. Focus on progressive improvement relative to your own baseline rather than comparing yourself to others with different genetic backgrounds.

The Role of Genetics vs. Lifestyle

While genetics determine your skeletal frame, muscle fiber distribution, and baseline metabolism, lifestyle factors including exercise habits, nutrition quality, sleep, stress management, and overall activity level have a profound impact on your actual body composition. Research suggests that genetics account for approximately 40-70% of body composition variation, meaning lifestyle factors control 30-60% of the equation. This is a substantial amount of influence. Consistent strength training can increase muscle mass in any body type, and strategic nutrition can optimize body fat levels regardless of metabolic predisposition. The key is working with your natural tendencies rather than fighting against them.

Beyond the Three-Type System

Modern exercise science has moved beyond rigid three-category classification. The Heath-Carter method, developed in the 1960s, rates individuals on a scale for each component (endomorphy, mesomorphy, ectomorphy) rather than assigning a single type. For example, someone might be rated 3-5-2, indicating moderate endomorphy, high mesomorphy, and low ectomorphy. This nuanced approach recognizes that most people are blends. Additionally, body composition changes throughout life due to aging, hormonal shifts, activity changes, and nutritional patterns, further demonstrating that body type is dynamic rather than fixed.

Common Mistakes to Avoid

• Using body type as an excuse: Saying "I am an endomorph so I cannot lose weight" or "I am an ectomorph so I cannot build muscle" limits your potential. Body type describes tendencies, not absolutes.
• Following body-type-specific diets rigidly: While body type can inform nutritional starting points, individual variation, activity level, health conditions, and personal preferences matter more. A balanced approach with adjustments based on results is more effective.
• Measuring wrist on the non-dominant hand: The dominant hand typically has a slightly larger wrist due to greater use. Measure the dominant wrist for consistency, or measure both and use the average.
• Comparing your body type to others: Body type classification helps you understand your own tendencies. Comparing yourself to someone with a fundamentally different skeletal structure leads to unrealistic expectations.
• Ignoring that body type can blend: Pure ectomorphs, mesomorphs, or endomorphs are rare. Most people display characteristics of two or even all three types. The classification is a spectrum, not three distinct boxes.

Frequently Asked Questions