I have created a Visualforce Email template, In the table, all record will show dynamically with respected grade value

Question

I have created a Visualforce Email template, In the table, all record will show dynamically with respected grade value. Now I want to add all grade value. How Can I proceed with that?

        <table>
            <tr>
               <th>Name</th>
               <th>Grade</th>                       
            </tr>
            <apex:repeat var="cn" value="{!relatedTo.Contact}">
            <tr>
               <td>{!cn.Name}</td> 
               <td>{!cn.Grade__c}</td>                     
            </tr>
            <tr>
                Total Grade :
            </tr>
            <td></td>
            </apex:repeat>                  
        </table>
        </body>

Answer 1

The official, proper way to do this is to create a Visualforce component. Visualforce-based emails can't have Apex controllers - but components can. And components can be embedded in emails. So you'd calculate the grand total in Apex, expose it as a class variable (or getter function) and simply display it.

You should have no problems searching for some samples, it's not rocket science if you've done some Apex+Visualforce in the past. My answer from a while ago could serve as a starting point although probably it's too complex for what you want to achieve.

---

The unofficial way to do it uses an undocumented behaviour of Visualforce <apex:variable> tag. Salesforce documentation explicitly says to not rely on it, it can break anytime. But - you could make it happen without any Apex code and that's very tempting (easier to maintain, no unit tests to write...). You've been warned.

<apex:variable var="grandTotal" value="{!0}" />
<apex:repeat var="cn" value="{!relatedTo.Contact}">
    <apex:variable var="grandTotal" value="{!grandTotal + cn.Grade__c}" />
    <tr>
        <td>{!cn.Name}</td> 
        <td>{!cn.Grade__c}</td>                     
    </tr>
</apex:repeat>
<tr>
    <td>Total Grade :</td>
    <td>{!grandTotal}</td>
</tr>