Indus Valley Had One of the Most Precise Ancient Rulers

Indus Valley Civilization inventions and discoveries include the step well, button, measuring weights, and rulers.

The Indus Valley Civilization established the oldest and most exact ancient ruler. It was composed of a copper-alloy bar and was originally known as the measuring rod. The ruler was first measured in a perfectly divisible format, with the entire ruler divided into uniform units equating to 3.55mm and labelled in an exact decimal subdivision within 0.005 inches. Aside from the uniform measurement, the fact that the smallest division on a scale (1.704mm) was calibrated during the Bronze Age makes it one of the most precise rulers in history.

Aside from that, the ruler used a binary decimal system that went from 1,2,4,8,16,32 to 12,800 units. Every bunch weighed in at roughly 0.85 grams.