<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>JS Bin</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bignumber.js/4.1.0/bignumber.min.js"></script>
<script>
function calc() {
var base = new BigNumber(256);
var hTargetCompact = '1d00ffff';
var e = hTargetCompact.slice(0,2); //First Byte
var exponent = new BigNumber(e,16);
//Three Significant Bytes less
exponent = exponent.minus(3);
var m = hTargetCompact.slice(2);
//Three Significant Bytes
var mantissa = new BigNumber(m,16);
var hTarget = mantissa.times(base.toPower(exponent));
var d = new BigNumber('1.19679269409879e12');
// Current Difficulty 1196792694098.79
var cTarget = hTarget.div(d).ceil();
// Output Current Target in Hex
console.log(cTarget.toString(16));
document.getElementById("ct").innerHTML = cTarget.toString(16);
// Average Network Hashrate
// D * 2 ** 32 / 600
var f = new BigNumber(7158278.83);
var avgNetHashRate = d.times(f).div(1000000000);
console.log(avgNetHashRate.toString()) // In GH/s
document.getElementById("anhr").innerHTML = avgNetHashRate.toString();
}
</script>
</head>
<body onload="calc()">
<h3> Bitcoin Current Target(Hex)</h3>
<div id="ct"></div>
<h3> Bitcoin Average Net Hash Rate(GH/s)</h3>
<div id="anhr"></div>
</body>
</html>