At what angle does the descending passage of the Great Pyramid slope?

The descending passage of the Great Pyramid slopes at about 26.5 degrees. Measurements give a more precise angle of approximately 26°26′46″, corresponding to a rise-to-run ratio of about 1 to 2.

This passage begins at the pyramid’s original north-side entrance and runs downward through the masonry before continuing into the bedrock beneath the monument. It ultimately leads toward the Subterranean Chamber, one of the pyramid’s three principal internal chambers. The passage is narrow and low, with a slanted height of roughly 1.2 meters and a width of about two royal cubits.

The descending passage is sometimes confused with the Ascending Passage, which leads upward toward the Grand Gallery. The ascending route has a similar but slightly different inclination, commonly given as about 26°6′. That small distinction matters when identifying which corridor a question describes.

The passage also illustrates the pyramid’s complex planning. Builders had to cut through both carefully placed masonry and the natural limestone bedrock, creating a route that extends well below the pyramid’s visible base.