WooCommerce display total price when quantity selection change

You're almost there... try this, paste this in your functions.php

add_action( 'woocommerce_single_product_summary', 'woocommerce_total_product_price', 31 );
function woocommerce_total_product_price() {
    global $woocommerce, $product;
    // let's setup our divs
    echo sprintf('<div id="product_total_price" style="margin-bottom:20px;">%s %s</div>',__('Product Total:','woocommerce'),'<span class="price">'.$product->get_price().'</span>');
    ?>
        <script>
            jQuery(function($){
                var price = <?php echo $product->get_price(); ?>,
                    currency = '<?php echo get_woocommerce_currency_symbol(); ?>';

                $('[name=quantity]').change(function(){
                    if (!(this.value < 1)) {

                        var product_total = parseFloat(price * this.value);

                        $('#product_total_price .price').html( currency + product_total.toFixed(2));

                    }
                });
            });
        </script>
    <?php
}

source: http://reigelgallarde.me/programming/show-product-price-times-selected-quantity-on-woocommecre-product-page/