Degrees decimal minutes to decimal degrees converter

Convert a latitude or longitude written in degrees and decimal minutes into one signed decimal-degree value. Enter a coordinate such as 40° 26.767′ N or 79 58.933 W. The converter identifies latitude or longitude from the hemisphere, validates the correct geographic range, divides the decimal minutes by sixty, and applies a negative sign for south or west. The response also preserves the parsed components and supplies a normalized coordinate for straightforward checking.

Recognize a degrees and decimal minutes coordinate

Degrees and decimal minutes, commonly abbreviated DDM, represents one geographic axis with an integer degree component, a decimal minute component, and a hemisphere letter. A latitude might be written as 40° 26.767′ N, while a longitude might appear as 79° 58.933′ W. The hemisphere is essential because it establishes both the axis and the sign: N and S indicate latitude, whereas E and W indicate longitude.

This converter accepts the hemisphere at either the beginning or the end, and it accepts a degree symbol or whitespace between the two numeric components. A straight apostrophe, a typographic prime, or the English word minute may follow the minute value. Do not include a latitude-longitude pair, seconds, a negative degree sign, or a bare number without a hemisphere.

Those forms represent different contracts or leave the sign ambiguous. Decimal minutes must be at least zero and strictly less than sixty, just as the minutes on a clock cannot reach sixty without carrying into the next degree. Keeping these components explicit makes field notes and navigation exports easy to inspect before conversion.

Understand the conversion and geographic limits

The arithmetic is direct: decimal degrees equal degrees plus decimal minutes divided by sixty. The converter first calculates that positive magnitude, then makes it negative when the hemisphere is south or west. For example, a western longitude with seventy-nine degrees and 58.933 decimal minutes becomes the negative of seventy-nine plus 58.933 divided by sixty.

North and east remain positive. This sign convention is widely used by mapping databases, GeoJSON workflows, spreadsheets, and spatial APIs. Validation depends on the axis inferred from the hemisphere.

Latitude cannot exceed ninety degrees, and longitude cannot exceed one hundred eighty degrees. At exactly a pole or the antimeridian limit, the minute component must be zero because any additional fraction would cross the valid range. The implementation does not silently wrap an excessive longitude or carry sixty minutes into another degree; it rejects malformed values so an upstream data problem remains visible.

Use the result safely in mapping workflows

Use this converter when a GPS receiver, aviation record, marine log, survey note, or geocaching listing provides a single coordinate in DDM but your destination expects decimal degrees. Convert latitude and longitude separately, then keep their axis labels attached until you assemble a pair. Many geographic formats name latitude first and longitude second, while GeoJSON coordinate arrays conventionally place longitude first; conversion does not resolve that ordering difference for you.

Preserve enough decimal places for the accuracy of the source rather than treating a long floating-point result as newly created precision. One thousandth of a minute corresponds to roughly a couple of metres in latitude, though longitude distance varies with latitude. The tool performs no datum transformation, geocoding, map lookup, or coordinate-system inference beyond the N, S, E, and W letters.

It assumes the DDM numbers already refer to the datum required by your workflow. Invalid input is rejected without inventing a location, which is especially important in emergency, surveying, and asset-management pipelines where a plausible but incorrect sign can move a point across the world.