degreesminutesseconds

Degreesminutesseconds, abbreviated DMS, is a system for expressing geographic coordinates as three components: degrees, minutes, and seconds. In this sexagesimal (base-60) scheme, one degree is divided into 60 minutes, and one minute into 60 seconds. Coordinates are typically presented with the degree symbol, a prime for minutes, and a double prime for seconds, for example 40° 26' 46" N, 79° 58' 56" W.

Notation and hemispheres: Latitude values range from 0° to 90°, and longitude from 0° to 180°. Each coordinate is usually followed by a hemisphere letter: N or S for latitude, E or W for longitude. Some datasets also use a leading minus sign to indicate south or west.

Conversions: DMS can be converted to decimal degrees with the formula decimal = D + M/60 + S/3600, applying the appropriate sign from the hemisphere. Conversely, decimal degrees can be converted to DMS by taking the integer degree part, then minutes = floor((|decimal| − D) × 60), and seconds = ((|decimal| − D) × 60 − minutes) × 60, with rounding as needed.

Usage and considerations: DMS remains common in traditional navigation, manual map annotations, surveying, and legal descriptions. Decimal degrees are often preferred in geographic information systems because they simplify arithmetic and reduce ambiguity; DMS can introduce interpretation errors if hemisphere information or rounding is not standardized.

Example: 40° 26' 46" N, 79° 58' 56" W corresponds to approximately 40.4461° N, −79.9822° E/W.