How many kilometers long is the Ming dynasty portion of the Great Wall?

The Ming dynasty portion of the Great Wall is about 8,851.8 kilometres long.

This figure comes from a comprehensive survey of the Ming defensive system, not merely a measurement of uninterrupted masonry. The total includes approximately 6,259.6 kilometres of wall sections, 359.7 kilometres of trenches and 2,232.5 kilometres of natural defensive barriers such as hills and rivers.

That distinction explains why different references may quote slightly different totals, including the rounded figure of about 8,850 kilometres. The Great Wall was never a single uniform wall; it was a network of fortifications built across varied terrain, with gaps where natural geography supplied part of the defence.

The Ming system generally ran from Jiayuguan in the west toward Shanhai Pass and the sea in the east, with additional routes extending toward Hushan in Manchuria. Earlier Qin, Han and other dynasties built separate wall systems, so the Ming measurement should not be confused with the total length of all Great Wall remains, which is much greater.