Pasted from FAQs, let me know for more help.

##### Q) How to enable footer summary row?

Please do these changes to enable footer summary row.

Step1: Enable footer row in options

$grid["footerrow"] = true;
…
$g->set_options($grid);

Step2: Add custom JS code as mentioned. 'list1' is the identifier for grid. In function 'getCol', 2nd param 'field1' is the name of column, which will show the summary data. Valid options for mathoperation (4th param) are – 'sum, 'avg', 'count'.

<div style="margin:0px;">
<script>
var opts = {

'loadComplete': function () {
var grid = $("#list1"),
sum = grid.jqGrid('getCol', 'field1', false, 'sum');
grid.jqGrid('footerData','set', {field1: 'Total: '+sum});
}
};
</script>

<?php echo $out?>
</div>