How many muscles are in the human body?

The usual answer is about 600 skeletal muscles, but published counts run from 600 to 850 depending on whether a muscle with several heads counts as one or several — the biceps has two heads, the triceps three, the quadriceps four, and treating each as a separate muscle adds hundreds. That is only the muscles you can consciously control. Smooth muscle lines the gut, the blood vessels and the airways, and cardiac muscle is a third type again; counting those as discrete muscles is not meaningful.

How the figure is arrived at

Dissection and convention. Because a muscle is defined by its origin, insertion and nerve supply, a structure with two origins can legitimately be described either way, and anatomists have never fully agreed. Any source giving a single precise number without stating its convention is over-claiming.

How confident it is

Low estimate

600

High estimate

850

Spread

1.4× between the bounds

Other the human body counts

• How many bones are in the human body? 206 in an adult — about 300 at birth
• How many cells are in the human body? about 30 trillion human cells, plus 38 trillion bacteria
• How many neurons are in the human brain? about 86 billion
• How many hairs are on your head? about 100,000
• How many taste buds do you have? about 2,000 to 8,000
• How long are all your blood vessels? commonly quoted as 100,000 km — but probably closer to 20,000
• How many base pairs are in human DNA? about 3.1 billion per copy — 6.2 billion in most cells