The largest body of water by volume is the Pacific Ocean. Covering an area of approximately 63 million square miles (165 million square kilometers), the Pacific Ocean holds more than half of the Earth’s total oceanic water, with an estimated volume of around 187 quintillion gallons (710 million cubic kilometers). This massive ocean is crucial for global weather patterns and marine biodiversity. It is bordered by various countries, including the United States, Japan, Australia, and several nations in Southeast Asia, making it a vital hub for international trade and travel, as well as rich in resources.