How is a decimal coordinate split into degrees, minutes and seconds?

The whole-number part is the degrees. Multiply the fractional part by 60 to get minutes; the whole part of that is the minutes. Multiply the remaining fraction by 60 again to get the seconds.

What range are valid latitude and longitude values?

Latitude must be between -90 and +90 degrees and longitude between -180 and +180 degrees. Values outside these ranges are not valid geographic coordinates.

How do the sign and the hemisphere letter relate?

A positive latitude is north (N) and a negative latitude is south (S). A positive longitude is east (E) and a negative longitude is west (W). The DMS form uses the letter instead of a minus sign.

Why does my converted value have 60 seconds rounded?

Rounding seconds to whole numbers can occasionally produce 60. This tool keeps a few decimal places of seconds to avoid that and to preserve precision; round only at display time if needed.

Lat/Lng to DMS Converter

This tool converts decimal latitude and longitude into DMS — degrees, minutes and seconds — the sexagesimal notation still used on nautical charts, aviation maps and many GPS receivers. Enter a signed decimal coordinate such as 51.507351, -0.127758 and get back 51°30'26.5" N, 0°7'39.9" W.

How it works

A decimal degree value is split into three parts. Take the absolute value of the coordinate, then:

degrees = floor(value)
minutes = floor((value - degrees) * 60)
seconds = (((value - degrees) * 60) - minutes) * 60

The original sign decides the hemisphere letter: positive latitude is N, negative is S; positive longitude is E, negative is W. Because there are 60 minutes in a degree and 60 seconds in a minute, the conversion is exact — only display rounding introduces any error.

Tips and notes

One second of latitude is roughly 31 metres, so keep a decimal place or two on the seconds for survey-grade precision. The conversion is purely arithmetic and runs entirely in your browser; no coordinates leave your device. To go the other way, use the DMS to Decimal converter.