Display product discount percentage(%) with saving price in woocommerce

This code will help you to display product discount percentage with saving price on woocommerce website. Just add below code to your function.php on your woo commerce theme

add_filter( 'woocommerce_get_price_html', 'change_displayed_sale_price_html', 10, 2 );
function change_displayed_sale_price_html( $price, $product ) {
    // Only on sale products on frontend and excluding min/max price on variable products
    if( $product->is_on_sale() && ! is_admin() && ! $product->is_type('variable')){
        // Get product prices
        $regular_price = (float) $product->get_regular_price(); // Regular price
        $sale_price = (float) $product->get_price(); // Active price (the "Sale price" when on-sale)

        // "Saving price" calculation and formatting
        $saving_price = wc_price( $regular_price - $sale_price );

        // "Saving Percentage" calculation and formatting
        $precision = 1; // Max number of decimals
        $saving_percentage = round( 100 - ( $sale_price / $regular_price * 100 ), 1 ) . '%';

        // Append to the formated html price
        $price .= sprintf( __('<p class="saved-sale">Save: %s <em>(%s)</em></p>', 'woocommerce' ), $saving_price, $saving_percentage );
    }
    return $price;
}