1. Great Hammerhead Shark (Sphyrna mokarran):
- Maximum length: Up to 19.5 feet (5.9 meters)
2. Scalloped Hammerhead Shark (Sphyrna lewini):
- Maximum length: Up to 13 feet (4 meters)
3. Smooth Hammerhead Shark (Sphyrna zygaena):
- Maximum length: Up to 12.6 feet (3.8 meters)
4. Bonnethead Shark (Sphyrna tiburo):
- Maximum length: Up to 5 feet (1.5 meters)
It's important to note that these measurements represent the maximum reported sizes for each species, and the majority of individuals may be smaller. Additionally, the size of hammerhead sharks can vary based on factors such as region, habitat, and availability of food.