The Five Oceans of the World: Ranked by Size

Modern geography recognizes five named oceans, listed here by surface area:

1. Pacific Ocean – 165.3 million km² (largest; > all land combined).
2. Atlantic Ocean – 106.5 million km².
3. Indian Ocean – 70.6 million km².
4. Southern (Antarctic) Ocean – 20.3 million km² (recognized 2000).
5. Arctic Ocean – 14.1 million km² (smallest; sometimes called a mediterranean sea of the Atlantic).

Key Notes

• Boundaries defined by IHO (International Hydrographic Organization).
• Southern Ocean delineated by Antarctic Circumpolar Current (60°S).
• Arctic Ocean is shallow, largely ice-covered, bordered by continents.
• All are interconnected—one global ocean system.