<script type="text/javascript">

function steamIDToProfile(steamID)
\{    
    var parts = steamID.split(":");
    
    var iServer = Number(parts[1]);
    var iAuthID = Number(parts[2]);
    
    var converted = "76561197960265728"

    lastIndex = converted.length - 1

    var toAdd = iAuthID * 2 + iServer;
    var toAddString = new String(toAdd)    
    var addLastIndex = toAddString.length - 1;

    for(var i=0;i<=addLastIndex;i++)
    \{
        var num = Number(toAddString.charAt(addLastIndex - i));
        var j=lastIndex - i;
        
        do
        \{
            var num2 = Number(converted.charAt(j));            
            var sum = num + num2;        
                    
            converted = converted.substr(0,j) + (sum % 10).toString() + converted.substr(j+1);    
        
            num = Math.floor(sum / 10);            
            j--;
        }
        while(num);
            
    }
    
    return converted;
}

function makeLink(profile)
\{
    return "<a href='http://steamcommunity.com/profiles/" + profile + "'>" + profile + "</a>"
}

</script>

<input id="input" type="text" value="SteamID here" onclick="this.onclick='';this.value=''">
<input type="submit" value="Convert" onclick ="document.getElementById('result').innerHTML = makeLink(steamIDToProfile(document.getElementById('input').value))" >

<div id="result">

</div>  

<a href="http://steamcommunity.com/profiles/Тут_результат_расчетной_формулы(76561197960265728 + Y + Z*2)>SteamID_который_ввожу_в_скрипте</a>