Convert Roman Actus (actus) to Nautical Mile (nmi) instantly.
About these units
Roman Actus (actus)
The Roman actus was an ancient Roman unit of length measuring 120 Roman feet, or about 35.5 meters. It played an essential role in Roman land surveying and agriculture, forming part of the system used to organize farms, roads, and territorial divisions in the expanding Roman world. The actus helped define a square unit of land known as the actus quadratus, which was used for taxation, distribution of land to soldiers, and standardizing plots throughout Roman colonies. Surveyors relied on tools like the groma to lay out straight lines based on actus subdivisions, giving Roman lands their characteristic grid patterns. Although long obsolete, the actus provides key insights into Roman engineering, colonial administration, and agricultural policy. Many European land patterns can trace their roots back to Roman measurement practices — a testament to the enduring legacy of Roman surveying.
Nautical Mile (nmi)
The nautical mile is a unit designed specifically for navigation. Its definition—exactly 1,852 meters—originated from the idea that one nautical mile equals one minute of arc along Earth's meridian. This geometric relationship makes nautical miles incredibly convenient for charting and navigation because latitude coordinates are given in degrees, minutes, and seconds. Aviation and maritime industries use nautical miles exclusively for distance, and knots (nautical miles per hour) for speed. Because Earth's shape and size are fundamental to navigational calculations, using nautical miles avoids the complexities that would arise if statute miles or kilometers were used instead. The unit remains globally standardized and universally understood in professional navigation.