How to show the percentage value of your discounts in WooCommerce

// =========================================================================
// SHOW THE PERCENTAGE VALUE OF DISCOUNT PRODUCTS
// =========================================================================
function woocommerce_custom_sales_price( $price, $regular_price, $sale_price ) {
    global $product;
    if( $product->has_child() ) {
        $var_regular_price = $product->get_variation_regular_price( 'min', true );
        $var_sale_price = $product->get_variation_price( 'min', true );
        
        $percentage = round( ( $var_regular_price - $var_sale_price ) / $var_regular_price * 100 ).'%';
        $percentage_txt = ' ' . __('<span class="sale-percentage"> -', 'woocommerce' , '</span>') . $percentage;
        $price = '<del>' . ( is_numeric( $regular_price ) ? wc_price( $regular_price ) : $regular_price ) . '</del> <ins>' . ( is_numeric( $sale_price ) ? wc_price( $sale_price ) . $percentage_txt : $sale_price . $percentage_txt ) . '</ins>';
        return $price;
    }
    else{
        $percentage = round( ( $regular_price - $sale_price ) / $regular_price * 100 ).'%';
        $percentage_txt = ' ' . __('<span class="sale-percentage"> -', 'woocommerce' , '</span>') . $percentage;
        $price = '<del>' . ( is_numeric( $regular_price ) ? wc_price( $regular_price ) : $regular_price ) . '</del> <ins>' . ( is_numeric( $sale_price ) ? wc_price( $sale_price ) . $percentage_txt : $sale_price . $percentage_txt ) . '</ins>';
        return $price;
    }
}
add_filter( 'woocommerce_format_sale_price', 'woocommerce_custom_sales_price', 10, 3 );