The Panama Canal is 50 miles (80 km) long from deep water in the Caribbean to deep water in the Pacific. The dredged portion of the canal has a minimum depth of about 40 feet (12 m) and a minimum width of 500 feet (152 m). Within the locks these dimensions are reduced, and ships with a draft of more than about 37 feet (11 m) or a beam (width) greater than 106 feet (32.3 m) cannot use the canal. A growing number of the world's largest ships are in this group.

There are six massive pairs of locks, each 1,000 feet (305 m) long and 110 feet (33.5 m) wide. Each may be filled or emptied in about 10 minutes, and each pair of lock gates takes about two minutes to open. Water is not pumped into and out of the locks, but flows from the artificial lakes through culverts. Electric towing locomotives called mules pull ships by cable through the locks. Most ships require six of these mules, three on each side.

Tidal ranges vary greatly from one side of the canal to the other. On the Pacific side the difference between high tide and low tide is about 12 feet (3.7 m), compared to less than 2 feet (61 cm) on the Caribbean side.

A ship crossing from the Caribbean Sea starts in Limon Bay. It proceeds at sea level for 6.5 miles (10.5 km) to Gatun, where it is raised 85 feet (26 m) to Gatun Lake by three locks. Then it travels 23.5 miles (37.8 km) through the lake to Gamboa, where it enters Gaillard (Culebra) Cut. After an 8-mile (13-km) trip through the cut the ship reaches Pedro Miguel locks, and is lowered 31 feet (9.4 m) in one step to Miraflores Lake. The two locks at the end of the lake lower the ship to sea level, and it travels another 8 miles (13 km) to the Pacific Ocean. The total passage time ranges from 8 to 15 hours. There are port facilities at both ends of the canal, at Balboa and Cristobal.

Most of the early traffic through the canal was to and from the United States. Since World War II, however, there has been a large increase in cargo moving to and from Europe and the Far East, especially Japan.