Display Magento Available Quantity in DropDown on list.phtml

 <select name="qty">
  <?php $i = 1 ?>
  <?php do { ?>
    <option value="<?php echo $i?>">
      <?php echo $i?>
      <?php $i++ ?>
    </option>
    <?php } while ($i <= (int)Mage::getModel('cataloginventory/stock_item')->loadByProduct($_product)->getQty()) ?>
</select>

Or try this


Set min_sale_qty of a product in backend, go to product inventory tab and find 'Minimum Qty Allowed in Shopping Cart' put desarable quantity there, we have to do this because we have to give equal interval between quantity in dropdow.

note: path can differ according to templete

app\design\frontend\base\default\template\checkout\cart\item\default.phtml

found quantity text box in that file and replace it with code below.

<?php $min_sale_qty = (int)Mage::getModel('cataloginventory/stock_item')->loadByProduct($this->getProduct())->getData('min_sale_qty');
    $total_qyt = (int)Mage::getModel('cataloginventory/stock_item')->loadByProduct($this->getProduct())->getQty();
     ?>
    <select name="cart[<?php echo $_item->getId() ?>][qty]">
    <?php for($i = $min_sale_qty; $i <= $total_qyt; $i = $i + $min_sale_qty)
      {
      ?>
    <option value="<?php echo $i?>">
      <?php echo $i?>
    </option>
   <?php }?>
   </select>