The current metro area population of Kumamoto in 2026 is 733,000, a 0.27% decline from 2025.

• The metro area population of Kumamoto in 2025 was 735,000, a 0.27% decline from 2024.
• The metro area population of Kumamoto in 2024 was 737,000, a 0.14% decline from 2023.
• The metro area population of Kumamoto in 2023 was 738,000, a 0.27% decline from 2022.