How Were the Pyramids Built? What We Know About the Great Pyramid

About 4,500 years ago, without cranes or modern machines, the ancient Egyptians raised more than two million stone blocks to build the Great Pyramid of Giza. How did they do it? Scientists have not uncovered every detail, but archaeological discoveries in recent decades have answered many of the big questions.

The Great Pyramid in numbers

The Great Pyramid was built for the pharaoh Khufu of the Fourth Dynasty and was most likely completed around 2560 BCE.

• Original height: about 146.6 metres; today about 138.5 metres, after losing its outer casing and capstone.
• Length of each side of the base: about 230 metres.
• Number of blocks: around 2.3 million.
• Average block weight: about 2.5 tonnes, while some granite blocks in the “King’s Chamber” weigh tens of tonnes.

The Great Pyramid remained the tallest human-made structure for about 3,800 years, and it is the only one of the Seven Wonders of the Ancient World still standing.

Who built the pyramids? Not slaves

The popular movie image of thousands of slaves under the whip is not supported by the evidence. In the 1990s, archaeologists discovered a workers’ village and workers’ tombs near the pyramids.

These finds show that the builders were organised work crews who received food such as bread, beer and meat, and had medical care: skeletons have been found with properly healed fractures. Many researchers estimate the workforce at any one time was in the thousands, possibly up to about 20,000 people, including permanent craftsmen and seasonal labourers.

Where did the stones come from?

• Limestone for the core: mostly quarried right on the Giza plateau.
• Fine white limestone for the outer casing: brought from the Tura quarries across the Nile.
• Granite: shipped from Aswan in the south, more than 800 kilometres away.

The Diary of Merer: a 4,500-year-old work log

In 2013, an archaeological team at Wadi al-Jarf on the Red Sea coast discovered the oldest inscribed papyri known so far. Among them is the logbook of an official named Merer, describing how his crew moved limestone blocks from Tura to Giza by boat along the Nile and through canals, late in Khufu’s reign.

The papyrus is direct evidence that the Nile was the “highway” for building materials.

Did you know? A wall painting in the tomb of the Egyptian official Djehutihotep shows a worker pouring water in front of a sledge carrying a colossal statue. Physics experiments in 2014 showed that wetting sand by the right amount greatly reduces friction, making heavy loads far easier to pull.

How did they lift the stones?

This is still debated. The main theories are:

1. A straight ramp rising with the pyramid, though it would have needed an enormous length near the top.
2. Zigzag ramps on the pyramid’s faces.
3. A spiral ramp wrapping around the outside of the pyramid.
4. An internal ramp climbing inside the pyramid’s body, a hypothesis proposed by French architect Jean-Pierre Houdin.

In 2018, a steep ramp flanked by staircases and post holes for wooden posts was found at the ancient Hatnub quarry, dating roughly to Khufu’s era. It suggests the Egyptians used clever hauling systems to pull blocks up steep slopes.

Most likely, the builders combined several methods depending on the stage of construction.

Astonishing precision

The sides of the Great Pyramid line up with the four cardinal directions (north, south, east and west) with remarkable accuracy, off by only a small fraction of a degree. Researchers believe the Egyptians used observations of the stars or the Sun to achieve this.

What about alien theories?

There is no scientific evidence for them. Instead, Egyptian civilisation left clear evidence of human work: quarries, tools, workers’ villages and administrative records like the Diary of Merer. Crediting this achievement to anyone else robs the ancient Egyptians of what they accomplished.

Frequently asked questions

Why did the Egyptians build pyramids?

They were monumental royal tombs, linked to beliefs about the king’s journey to the afterlife and his union with the Sun.

How long did it take to build the Great Pyramid?

Ancient accounts say about 20 years, and many researchers consider that a reasonable estimate.

How many pyramids are there in Egypt?

Archaeologists have found more than 100 pyramids in Egypt, varying widely in size and condition.

Key takeaway

The pyramids were built by organised human effort: skilled, fed and cared-for workers, stones moved by boat along the Nile and on sledges over wet sand, and ramps whose exact design scientists are still studying. They are a testament to brilliant engineering and management thousands of years ago.