See the body. Size by size.
Turn a 3D body 360°, compare BMI, grow or shrink muscle groups in inches or centimeters, see what belly fat does, and explore every superficial muscle with exercises you can watch right here.
Your body
BMI is weight divided by height squared, a quick screening number for adults. It cannot tell muscle from fat, and it is not a diagnosis. The body shown is an average illustration for that BMI.
Belly shape & visceral fat
Visceral fat sits deep around the organs, so it cannot be judged from looks alone. Press X-ray on the model to see it as a yellow mass. Real measurements need a waist tape, imaging, or a clinician.
Muscle groups, in cm or inches
Drag a slider to grow or shrink a group. The measurement updates live, the camera zooms to it, the muscles light up red and a tape shows the true circumference.
Muscle atlas & exercises
Switch the model to Muscle atlas to see each superficial muscle, as in an anatomy plate. Tap one to light it red, and pick a muscle below to read what it does and watch how to train it.
About this tool
An educational illustration, not medical advice. Bodies are generated from open CC0 human-shape data; sizes are indicative. The muscle atlas is a simplified plate of the superficial muscles, with deep muscles (for example the rhomboids and the rotator cuff beneath other muscles) drawn at their approximate surface position. The soda can is a standard 12 fl oz beverage can (2.6 in wide, 4.8 in tall) for scale. Exercise videos come from US-based fitness professionals and play inside this page; AINutry has no commercial relationship with them. Talk with a clinician or qualified trainer before changing your training or diet.
How to use the 3D body lab
Enter height and weight to see your BMI and a body at that BMI. Try the BMI shortcuts from 17 to 42. At some heights the 3D body reaches its limit and says so, and your numbers are still used for BMI.
Drag any group (upper arm, chest, thigh, calf, waist and more) by inches or centimeters. The camera zooms in, a tape shows the real circumference, and the soda can gives a size reference.
Switch to Muscle atlas. Every superficial muscle is drawn like an anatomy plate. Tap one to light it red, learn what it does and watch how to train it.
Frequently asked questions
What is BMI and what does it miss?
Body mass index is weight in kilograms divided by height in meters squared. It is a quick screening number for adults. It does not separate muscle from fat or show where fat sits, so a muscular person can have a high BMI without excess body fat. Use it as a starting point, not a verdict.
What is visceral fat and why does waist-to-height ratio matter?
Visceral fat is stored deep in the abdomen around organs. It cannot be seen from the outside. A simple proxy is waist-to-height ratio: many health guidelines suggest keeping your waist under half of your height. The viewer illustrates how a larger abdomen changes the body shape. It is not a measurement of your own body.
How accurate are the muscle sizes?
Sizes come from circumference measurements on open-source human body shapes and are indicative, not personal predictions. Real growth depends on genetics, training, nutrition and time.
Where do the exercise videos come from?
They are tutorials by US-based fitness and rehabilitation professionals with large audiences, in English, played inside this page through the privacy-enhanced YouTube player. They load only when you press play.