convert from long/lat to google mercator (or EPSG:4326 to EPSG:900913)

degress2meters.js

var degrees2meters = function(lon,lat) {
        var x = lon * 20037508.34 / 180;
        var y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
        y = y * 20037508.34 / 180;
        return [x, y]
}

x= -77.035974
y = 38.898717

console.log(degrees2meters(x,y))

// should result in: -8575605.398444, 4707174.018280