KPI Dashboard using SharePoint List

<script type="text/javascript">

//

// Text to HTML

//

var theTDs = document.getElementsByTagName("TD");

var i=0;

var TDContent = " ";

while (i < theTDs.length) {

try {

TDContent = theTDs[i].innerText || theTDs[i].textContent;

if ((TDContent.indexOf("<DIV") == 0) && (TDContent.indexOf("</DIV>") >= 0)) {

theTDs[i].innerHTML = TDContent;

}

}

catch(err){}

i=i+1;

}

//

// ExpGroupRenderData overwrites the default SharePoint function

// This part is needed for collapsed groupings

//

function ExpGroupRenderData(htmlToRender, groupName, isLoaded) {

var tbody=document.getElementById("tbod"+groupName+"_");

var wrapDiv=document.createElement("DIV");

wrapDiv.innerHTML="<TABLE><TBODY id=\"tbod"+ groupName+"_\" isLoaded=\""+isLoaded+ "\">"+htmlToRender+"</TBODY></TABLE>";

var theTBODYTDs = wrapDiv.getElementsByTagName("TD"); var j=0; var TDContent = " ";

while (j < theTBODYTDs.length) {

try {

TDContent = theTBODYTDs[j].innerText || theTBODYTDs[j].textContent;

if ((TDContent.indexOf("<DIV") == 0) && (TDContent.indexOf("</DIV>") >= 0)) {

theTBODYTDs[j].innerHTML = TDContent;

}

}

catch(err){}

j=j+1;

}

tbody.parentNode.replaceChild(wrapDiv.firstChild.firstChild,tbody);

}

</script>

Update: For SharePoint 2013, Use the below code in Script editor:

 <script type="text/javascript" src="http://www.google.com/jsapi"></script>
 <script type="text/javascript">
     //load jQuery
     google.load("jquery", "1.2.6");
 </script>
 <script type="text/javascript">
 //make a fn for reuse
 $.calcHTML = function() {
     //loop through TDs moving text node to html
     $("td.ms-vb2,td[id$='Calculated'],td.ms-stylebody,td.ms-formbody").filter(":contains(<DIV)").each(function(){
         $(this).html($(this).text());
     });
 };
 //call calcHTML on DOM ready for ungrouped rows
 $(function() {
     $.calcHTML();
     if (showpreview1) { //check for preview script
         $("td.ms-vb-title").bind("mouseover", function(){
             showpreview1(this);
             $.calcHTML();
         });
     }
 });
 //replace ExpGroupRenderData, call calcHTML for grouped rows
 function ExpGroupRenderData(htmlToRender, groupName, isLoaded) {
     $("#tbod"+groupName+"_").attr("isloaded",isLoaded).html(htmlToRender).show("fast",$.calcHTML());
 }
 </script>

Thanks to: https://www.nothingbutsharepoint.com/sites/eusp/pages/jquery-for-everyone-html-calculated-column-plugin.aspx

Alternate approach: Using Dataview web part to Design KPI Dashboard

Same thing can be achieved using SharePoint Designer & Dataview webpart. Just convert the existing List view to XSLT Dataview and set the conditional formatting as in below images.
 Set the conditional formatting style: