Calculate distance in meters when you know longitude and latitude in java

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Working with latitude/longitude values in Java

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I need to calculate the distance between two points given by two coordinates. The project I am working on is a Java-project, so Java-code will be great, but pseudo-code can also be given, then I can implement it myself :)

As you probably know, there are three ways to represent coordinates:

Degrees:Minutes:Seconds (49°30'00"N, 123°30'00"W)
Degrees:Decimal Minutes (49°30.0', -123°30.0'), (49d30.0m,-123d30.0')
Decimal Degrees (49.5000°,-123.5000°), generally with 4-6 decimal numbers.

It's the third way my coordinates are given in, so the code for this values will be preferred :)

Just out of curiosity. As the earth isnt a perfect sphere, (equatorial radius of 6,378.137 km and a polar radius of 6,356.752 km.) How large would the error be? 3958.75 miles in the answer below isan approximation using the volumetric radius — KarlP, May 08 '09 at 12:32
See the Vicenty formula -- http://www.movable-type.co.uk/scripts/latlong-vincenty.html -- if you care about the Earth not quite being a sphere — mob, Nov 10 '09 at 23:22
I used the code from this site successfully: * [Longditude and latitude calculation](http://www.zipcodeworld.com/samples/distance.java.html) I had to make some calculations on the answers to make it into european meters, but that was pretty straight forward :) — Espen Herseth Halvorsen, May 08 '09 at 01:48
Take a look at [GeoTools](http://geotools.codehaus.org/)' `org.geotools.referencing.GeodeticCalculator`. Set the starting and ending position then get call [`getOrthodromicDistance()`](http://docs.geotools.org/latest/javadocs/org/geotools/referencing/GeodeticCalculator.html#getOrthodromicDistance%28%29) which returns the orthodromic (great circle) distance. — Steve Kuo, May 08 '09 at 03:45
Take a look at this latitude/longitude distance calculator. It has a link to relevant source code (including an explanation) and a link to the math behind the calculation. It's actually pretty interesting. — lc., May 08 '09 at 01:42
If you understand mathematical formulas then this page should be more than enough to calculate distance between two points in any programming language. [http://en.wikipedia.org/wiki/Geographical_distance](http://en.wikipedia.org/wiki/Geographical_distance) — jan, May 08 '09 at 11:21
[This site](http://www.movable-type.co.uk/scripts/latlong.html) shows you the formula which is the part I assume you are having trouble with? You might want to specify if you want a straight line from point A to point B (through Earth) or if you want the distance as presented on the site. I'm sorry I don't exactly recall their names. However, the code seems relatively straightforward. — nevets1219, May 08 '09 at 01:43

score 193 · Accepted Answer · edited May 23 '17 at 12:10

193

Based on another question on stackoverflow, I got this code.. This calculates the result in meters, not in miles :)

 public static float distFrom(float lat1, float lng1, float lat2, float lng2) {
    double earthRadius = 6371000; //meters
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
               Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
               Math.sin(dLng/2) * Math.sin(dLng/2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    float dist = (float) (earthRadius * c);

    return dist;
    }

edited May 23 '17 at 12:10

Community

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answered May 08 '09 at 02:11

Espen Herseth Halvorsen

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Why convert to Float and then back to float? – Steve Kuo May 08 '09 at 04:05
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`return (float) (dist * meterConversion)` – mob Nov 10 '09 at 23:18
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The earth radius is 3958.75 in *miles* not kilometers. So your code above returns miles. – swinefeaster Nov 12 '11 at 08:55
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@swinefeaster: There's meterConversion constant in the second to last line which turns miles into meters. – Keith Irwin Nov 21 '11 at 02:30
The earth is not a perfect sphere, so this solution results in a slight error. – Steve Kuo Mar 15 '12 at 22:35
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Just use 6369 as the earthRadius rather than Miles and then convert them to metric afterwards. – Eric Darchis Apr 13 '12 at 15:02
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Well, it does not really matter but the earth radius is around **6371 km** not 6369 km :) – stevo.mit Nov 12 '13 at 15:30
i am getting float value like this "1.2720568E-4",here i cant split the first tow decimal values..what to do? – Karthick M Nov 14 '14 at 06:53
@KarthickM Are you trying to output the float? That's what happens when you cast a float to a string. Read this for outputing floats and doubles. [stackoverflow.com/questions/15322437](http://stackoverflow.com/questions/15322437) – Kayla Jan 13 '15 at 15:52
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Just to be precise... this returns values in **KILOMETERS**, not in **METERS** – Bartek Lipinski Feb 10 '15 at 17:31
Earth Radius is correct. See http://en.wikipedia.org/wiki/Earth_radius – Volodymyr Kulyk Apr 10 '15 at 09:35
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Can "a" ever be negative? – Xi Wei Dec 10 '15 at 23:45
using the coordinate -20.440263, -54.596051 I got a error because "a" is negative. – Felipe Andrade Nov 11 '16 at 18:21
Why don't you use doubles (input coordinates and output distanceInKm)? Would make the code a bit cleaner/smaller ... Just wondering if there is a reason which I don't see. – hb0 Feb 19 '18 at 12:54
@EricDarchis Is it route distance or Air Distance? – Hanry Oct 11 '18 at 07:48
I answered with kotlin version of Haversine formula here https://stackoverflow.com/a/57346001/5788341 – Binakot Aug 04 '19 at 11:00
hey so I can use this as a geofence right???? The geofence code on android is not working for me for some unknown reason and I was thinking to use this as an alternative – Pemba Tamang Aug 29 '19 at 13:24

score 27 · Answer 2 · edited Apr 07 '13 at 18:01

You can use the Java Geodesy Library for GPS, it uses the Vincenty's formulae which takes account of the earths surface curvature.

Implementation goes like this:

import org.gavaghan.geodesy.*;

...

GeodeticCalculator geoCalc = new GeodeticCalculator();

Ellipsoid reference = Ellipsoid.WGS84;  

GlobalPosition pointA = new GlobalPosition(latitude, longitude, 0.0); // Point A

GlobalPosition userPos = new GlobalPosition(userLat, userLon, 0.0); // Point B

double distance = geoCalc.calculateGeodeticCurve(reference, userPos, pointA).getEllipsoidalDistance(); // Distance between Point A and Point B

The resulting distance is in meters.

score 4 · Answer 3 · edited Dec 17 '09 at 20:01

4

In C++ it is done like this:

#define LOCAL_PI 3.1415926535897932385 

double ToRadians(double degrees) 
{
  double radians = degrees * LOCAL_PI / 180;
  return radians;
}

double DirectDistance(double lat1, double lng1, double lat2, double lng2) 
{
  double earthRadius = 3958.75;
  double dLat = ToRadians(lat2-lat1);
  double dLng = ToRadians(lng2-lng1);
  double a = sin(dLat/2) * sin(dLat/2) + 
             cos(ToRadians(lat1)) * cos(ToRadians(lat2)) * 
             sin(dLng/2) * sin(dLng/2);
  double c = 2 * atan2(sqrt(a), sqrt(1-a));
  double dist = earthRadius * c;
  double meterConversion = 1609.00;
  return dist * meterConversion;
}

edited Dec 17 '09 at 20:01

user85421

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answered Dec 10 '09 at 13:58

jessn

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Can "a" ever be negative? – Xi Wei Dec 10 '15 at 23:46
@XiWei No. Latitudes are between -pi/2 and pi/2 so their cosines are positives. And the other factors are squared. – Dawood ibn Kareem Apr 26 '17 at 09:08

Calculate distance in meters when you know longitude and latitude in java

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