centésimal

Centésimal is an adjective and noun used to describe systems, measurements, or notations based on the number 100. In mathematics and measurement, the term is most often associated with a decimalized, base-100 subdivision of quantities, including the centesimal division of the circle into 100 parts per quadrant.

In angle measurement, the centesimal system divides a circle into 400 equal parts called grads or gons. A right angle is 100 grads, and a full circle is 400 grads. Consequently, 1 grad equals 0.9 degrees. The centesimal degree system, sometimes called the gradian, was introduced in the late 18th century during the French decimal reform of measurements. Although it never supplanted degrees globally, it has persisted in some technical fields and in certain surveying and navigation contexts.

In arithmetic, centésimo refers to the hundredth part of a unit, and centésimos denote hundredths. The term centésimal is used in several Romance languages to describe fractions whose denominators are powers of 100, or more generally any notation tied to a base-100 concept. For example, centésimas are hundredth parts of a whole.

Etymology-wise, centésimal comes from Latin centesimus, meaning “one hundredth.” The term is used across languages to distinguish hundred-based divisions from decimal (base-10) or other bases. In modern usage, centésimal concepts appear primarily in specialized mathematical, metrological, and historical discussions, with degrees in the centesimal system retained mainly in niche applications. See also: degree, gradian, gon, percent, decimal fractions.