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copied!<p>As pointed out in a comment to your question, you should use Vincenty's formula for inverse problem. </p> <p>Answer to your question is: 111595.75 metres (or 60.257 nautical miles).</p> <p>Javascript implementation of Vincenty's inverse formula, as copied from <a href="http://jsperf.com/vincenty-vs-haversine-distance-calculations" rel="nofollow">http://jsperf.com/vincenty-vs-haversine-distance-calculations</a>:</p> <pre><code>/** * Calculates geodetic distance between two points specified by latitude/longitude using * Vincenty inverse formula for ellipsoids * * @param {Number} lat1, lon1: first point in decimal degrees * @param {Number} lat2, lon2: second point in decimal degrees * @returns (Number} distance in metres between points */ function distVincenty(lat1, lon1, lat2, lon2) { var a = 6378137, b = 6356752.314245, f = 1 / 298.257223563; // WGS-84 ellipsoid params var L = (lon2 - lon1).toRad(); var U1 = Math.atan((1 - f) * Math.tan(lat1.toRad())); var U2 = Math.atan((1 - f) * Math.tan(lat2.toRad())); var sinU1 = Math.sin(U1), cosU1 = Math.cos(U1); var sinU2 = Math.sin(U2), cosU2 = Math.cos(U2); var lambda = L, lambdaP, iterLimit = 100; do { var sinLambda = Math.sin(lambda), cosLambda = Math.cos(lambda); var sinSigma = Math.sqrt((cosU2 * sinLambda) * (cosU2 * sinLambda) + (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda) * (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda)); if (sinSigma == 0) return 0; // co-incident points var cosSigma = sinU1 * sinU2 + cosU1 * cosU2 * cosLambda; var sigma = Math.atan2(sinSigma, cosSigma); var sinAlpha = cosU1 * cosU2 * sinLambda / sinSigma; var cosSqAlpha = 1 - sinAlpha * sinAlpha; var cos2SigmaM = cosSigma - 2 * sinU1 * sinU2 / cosSqAlpha; if (isNaN(cos2SigmaM)) cos2SigmaM = 0; // equatorial line: cosSqAlpha=0 (§6) var C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha)); lambdaP = lambda; lambda = L + (1 - C) * f * sinAlpha * (sigma + C * sinSigma * (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM))); } while (Math.abs(lambda - lambdaP) > 1e-12 && --iterLimit > 0); if (iterLimit == 0) return NaN // formula failed to converge var uSq = cosSqAlpha * (a * a - b * b) / (b * b); var A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq))); var B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq))); var deltaSigma = B * sinSigma * (cos2SigmaM + B / 4 * (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) - B / 6 * cos2SigmaM * (-3 + 4 * sinSigma * sinSigma) * (-3 + 4 * cos2SigmaM * cos2SigmaM))); var s = b * A * (sigma - deltaSigma); s = s.toFixed(3); // round to 1mm precision return s; } </code></pre>

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