Britannica Sources used in this answer

What is the strongest muscle in the human body based on its size?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Illustration of the human muscular system from a side view, showing detailed muscles throughout the body with labels identifying major muscles in the head, torso, arms, and legs. — human muscle system Lateral view of the human muscular system.

The strongest muscle in the human body, when measured by its force relative to its size, is the masseter. This muscle is located in the jaw and is primarily responsible for chewing. It originates from the zygomatic bone (cheekbone) and inserts at the rear of the mandible (jawbone). The masseter's powerful action allows for the raising of the mandible, making it crucial for mastication. While other muscles may be larger overall, the masseter's efficiency in generating force for its size makes it exceptionally strong.123