Quick answer: How long did it take to build the great pyramid? 20 years.
Exactly how long it took to build the Great Pyramid of Giza is estimated at 20 years. The start date is lost in history but the best estimation has construction beginning around 2580 BC and ending around 2560 BC. The great pyramid is one of the Seven Wonders of the World and was the tallest man made structure for nearly 4000 years.