Ancient Architecture

The Egyptian Royal Cubit: Building the Great Pyramids

Learn how ancient Egyptian architects used the royal cubit of 20.6 inches to align the Pyramids of Giza with absolute precision.

By Ramses Hassan
Featured Image: /images/blog-pyramids.jpg

The Great Pyramid of Giza is one of the ancient wonders of the world, celebrated for its geometric accuracy. Behind this architectural marvel was a highly sophisticated standard of measurement: the Egyptian Royal Cubit.

The Length of the Royal Cubit

Unlike the common cubit which was 6 palms wide (about 18 inches), the Egyptian Royal Cubit was 7 palms wide. Physical rods uncovered from ancient tombs measure between 52.3 cm and 52.9 cm (approximately 20.6 inches or 1.72 feet). You can see the full breakdown of this measurement in our Cubit to Inches converter.

This rod was subdivided into 28 digits (each palm containing 4 digits). The digits were further split into fractional parts, allowing architects to measure down to a sixteenth of a digit.

The Pyramid of Giza in Royal Cubits

The base of the Great Pyramid of Giza originally measured exactly 440 royal cubits on each side. Converting this to feet:

The height of the pyramid was 280 royal cubits:

  • 280 royal cubits × 1.7188 feet = 481.3 feet

This base-to-height ratio (440 to 280) simplifies to 11:7, which closely relates to the mathematical constant Pi (22/7), demonstrating the mathematical genius of the ancient Egyptians.