How to convert lat long from decimal degrees to DMS format?

Question

Assuming I have a latitude longitude: 38.898556, -77.037852. How do I convert this to DMS?

Expected output is:

38 53 55 N
77 2 16 W

Want to be able to accept both a latitude and longitude as input parameters in the function.

Current function is as follows:

function convertDMS( lat, lng ) {

        var convertLat = Math.abs(lat);
        var LatDeg = Math.floor(convertLat);
        var LatMin = (Math.floor((convertLat - LatDeg) * 60));
        var LatCardinal = ((lat > 0) ? "n" : "s");

        var convertLng = Math.abs(lng);
        var LngDeg = Math.floor(convertLng);
        var LngMin = (Math.floor((convertLng - LngDeg) * 60));
        var LngCardinal = ((lng > 0) ? "e" : "w");

        return LatDeg + LatCardinal + LatMin  + "    " + LngDeg + LngCardinal + LngMin;
}

Answer 1

convert LAT & LNG to DMS

function toDMS(deg) {
    var d = Math.floor(deg);
    var min = Math.floor((deg - d) * 60);
    var sec = ((deg - d - min / 60) * 3600).toFixed(2);
    return d + "°" + min + "'" + sec + "\"";
}

function convertLatLngToDMS(lat, lng) {
    var latDMS = lat >= 0 ? "N" : "S";
    var lngDMS = lng >= 0 ? "E" : "W";
    
    lat = Math.abs(lat);
    lng = Math.abs(lng);
    
    var latDMSString = toDMS(lat);
    var lngDMSString = toDMS(lng);
    
    return latDMSString + " " + latDMS + " " + lngDMSString + " " + lngDMS;
}

USAGE:

const lat = 64.75960;
const lng = -104.21007;

const dms = convertLatLngToDMS(lat, lng)
console.log(dms); // 64°45'34.56" N 104°12'36.25" W

Answer 2

Here is a shorter solution to convert lat long from decimal degrees to the DMS format:

I have used the separator "/" between the lat and long, but that can be removed if you prefer.

function toDMS(lat,long) {
const toDMS=coord=>{min=~~(minA=((a=Math.abs(coord))-(deg=~~a))*60);
return deg+"° "+min+"' "+Math.ceil((minA-min)*60)+'"';
};
return `${lat>=0?"N":"S"} ${toDMS(lat)} / ${long>=0?"E":"W"} ${toDMS(long)}`;
}

// examples
console.log(toDMS( 22.22222, 11.11111));
console.log(toDMS( -22.22222, -11.11111));

Answer 3

here's two simple functions i created for this; just give the dms to the script

function ConvertDMSToDEG(dms) {   
    var dms_Array = dms.split(/[^\d\w\.]+/); 
    var degrees = dms_Array[0];
    var minutes = dms_Array[1];
    var seconds = dms_Array[2];
    var direction = dms_Array[3];

    var deg = (Number(degrees) + Number(minutes)/60 + Number(seconds)/3600).toFixed(6);

    if (direction == "S" || direction == "W") {
        deg = deg * -1;
    } // Don't do anything for N or E
    return deg;
}

and visa versa just give the degrees to the script, and true of false for lat (latitude)

function ConvertDEGToDMS(deg, lat) {
    var absolute = Math.abs(deg);

    var degrees = Math.floor(absolute);
    var minutesNotTruncated = (absolute - degrees) * 60;
    var minutes = Math.floor(minutesNotTruncated);
    var seconds = ((minutesNotTruncated - minutes) * 60).toFixed(2);

    if (lat) {
        var direction = deg >= 0 ? "N" : "S";
    } else {
        var direction = deg >= 0 ? "E" : "W";
    }

    return degrees + "°" + minutes + "'" + seconds + "\"" + direction;
}

hope this helps people..

Answer 4

I decided to simplify your math and do things in separate steps. I'm one degree off from your answer, so I'm going to chalk that up to a rounding issue -- I don't know the exact rules to do the convert.

var src = [38.898556, -77.037852];


// 38 53 55 N
// 77 2 16 W

function convertToDMS(src) {
  function toDMS(n) {
    // The sign doesn't matter
    n = Math.abs(n);

    // Get the degrees
    var d = Math.floor(n);
    // Strip off the answer we already have
    n = n - d;
    // And then put the minutes before the '.'
    n *= 60;
    
    // Get the minutes
    var m = Math.floor(n);
    // Remove them from the answer
    n = n - m;
    // Put the seconds before the '.'
    n *= 60;
        
    // Get the seconds
    // Should this be round? Or rounded by special rules?
    var s = Math.floor(n);

    // Put it together.
    return "" + d + " " + m + " " + s;

  }

  var dir0 = src[0] > 0 ? "N" : "S";
  
  var dir1 = src[1] > 0 ? "E" : "W";
  
  
  
  
  console.log(toDMS(src[0]) + dir0);
  console.log(toDMS(src[1]) + dir1);

}


convertToDMS(src);

Answer 5

function toDegreesMinutesAndSeconds(coordinate) {
    var absolute = Math.abs(coordinate);
    var degrees = Math.floor(absolute);
    var minutesNotTruncated = (absolute - degrees) * 60;
    var minutes = Math.floor(minutesNotTruncated);
    var seconds = Math.floor((minutesNotTruncated - minutes) * 60);

    return degrees + " " + minutes + " " + seconds;
}

function convertDMS(lat, lng) {
    var latitude = toDegreesMinutesAndSeconds(lat);
    var latitudeCardinal = lat >= 0 ? "N" : "S";

    var longitude = toDegreesMinutesAndSeconds(lng);
    var longitudeCardinal = lng >= 0 ? "E" : "W";

    return latitude + " " + latitudeCardinal + "\n" + longitude + " " + longitudeCardinal;
}

Here's an explanation on how this code works:

• The processing method for the latitude and longitude is pretty much the same, so I abstracted that out to the toDegreesMinutesAndSeconds function. That will return a string that will show, well, degrees, minutes, and seconds.
  • This function will start with the coordinate and truncate it. This value, in positive, is your amount of degrees.
  • The decimal portion needs to be converted to minutes. We take what's left from that rounding and we multiply it by 60.
  • We apply the same logic to get the seconds: so we use only the truncated number for our string but we keep the non-truncated to get the decimal part.
• Finally, we check if the original value of the coordinate was positive or negative. For latitude, positive (or zero) is North, otherwise South. For longitude, positive (or zero) is East, otherwise, West.