Convert between DMS and decimal degrees with bidirectional modes, radians output, arc-minute/second totals, and world landmarks reference.
This converter switches between degrees-minutes-seconds notation and decimal degrees. It is useful for GPS coordinates, mapping tools, surveying records, astronomy references, and any workflow where one system uses DMS while another expects a single decimal value. A latitude or longitude may be copied from a chart, a receiver, or a survey note, and the page makes it easy to restate that same angle in the format a digital system expects.
The page handles both directions, including north/south and east/west signs, and also shows radians plus total arc-minutes and arc-seconds. That makes it useful both for geographic coordinates and for general angular work. Because the related angular units appear together, you can check whether a value was entered as a coordinate, a bearing, or a plain angle before using it elsewhere.
Use it when a coordinate or angle needs to move cleanly between the traditional DMS format and the decimal format used by many digital systems. The side-by-side outputs help prevent sign mistakes and make conversion chains easier to verify.
DMS is readable and traditional for navigation and coordinates, while decimal degrees are easier for software and calculation. This page bridges those formats directly and keeps the supporting angular units in one place, which makes it easier to move between field notes, maps, and digital tools without re-entering the same coordinate twice.
DMS to DD: DD = Degrees + Minutes/60 + Seconds/3600 (negative for S/W). DD to DMS: D = floor(|DD|), M = floor((|DD| − D) × 60), S = ((|DD| − D) × 60 − M) × 60. Radians = DD × π / 180.
Result: 40° 26' 46" N = 40.446111° = 0.706145 rad
Converting 40 degrees, 26 minutes, 46 seconds North gives decimal degrees 40.446111 (approximately New York City latitude).
Three main formats exist for expressing geographic coordinates: Decimal Degrees (DD), Degrees and Decimal Minutes (DDM), and Degrees, Minutes, and Seconds (DMS). Each has its use cases — DMS for navigation charts, DD for GIS software, and DDM for some marine applications.
Decimal degree precision maps directly to ground distance: 1 decimal place ≈ 11.1 km, 2 ≈ 1.1 km, 3 ≈ 111 m, 4 ≈ 11.1 m, 5 ≈ 1.1 m, 6 ≈ 0.11 m. Most mapping applications use 6 decimal places, equivalent to about a hand's width on the ground.
The sexagesimal (base-60) system used for DMS dates back to ancient Babylon. It survives in timekeeping (60 seconds per minute, 60 minutes per hour) and in angle measurement. Despite the metric system's prevalence, DMS remains standard in navigation and astronomy.
DMS stands for Degrees, Minutes, Seconds, a way to express angles in a base-60 system. One degree contains 60 minutes and one minute contains 60 seconds, so the format is common in navigation and astronomy.
Add the degrees plus minutes divided by 60 plus seconds divided by 3600. For 40° 26' 46", that becomes 40 + 26/60 + 46/3600 = 40.4461°. Apply a negative sign for South or West values.
Four decimal places give about 11 m accuracy, five places give about 1.1 m, and six places give about 0.11 m. For most mapping uses, six decimal places is enough detail to identify a specific point.
D (decimal degrees) is a single decimal value, such as 40.4461°. DM (degrees decimal minutes) uses degrees plus a decimal minute value, and DMS uses degrees, minutes, and seconds, but all three represent the same angle.
360 degrees equals 2π radians, so the conversion uses the fixed ratio π/180. One radian is about 57.2958 degrees, which is why radians are more convenient in many formulas.
Decimal degrees are easier for computers to process and store than three separate components. Distance calculations, comparisons, and sorting are simpler when the coordinate is a single number.