Great Wall Build Years Calculator

How long did it take to build the Great Wall of China?

There was never one big push to build the Great Wall of China. Work stretched over roughly 2,000 years, starting in the 7th century BC (the Spring and Autumn states) and trailing off in the 17th century AD when the Ming dynasty fell. After unifying China in 221 BC, Qin Shi Huang stitched the older walls together into one defensive line. Most of what tourists see now is brick and stone laid down by the Ming dynasty (1368-1644). When China's State Administration of Cultural Heritage surveyed the whole thing in 2012, branches included, they came up with 21,196 km. The formula is years = km_total / km_per_year. Keep up a steady 100 km a year and those 21,196 km work out to about 212 years of actual building.

Applications

Handy if you're mapping out a tourism trip near Beijing, where the Badaling, Mutianyu and Jinshanling sections are. It also helps with history assignments that line up the Chinese imperial dynasties, and it fills in the backstory behind the wall's UNESCO World Heritage listing back in 1987.

FAQ

Is the wall visible from space? No. Both NASA astronauts and China's Yang Liwei have said you can't pick it out with the naked eye from low Earth orbit.

Which dynasty built the most? That would be the Ming, responsible for around 8,850 km of the surviving stretches. They worked with bricks, lime mortar and rammed earth cores.

Is the wall a single line? No. Think of it more as a web of parallel walls, branches and watchtowers spread across northern China rather than one unbroken barrier.