WooCommerce - Sale label to percentage %

functions.php

add_filter( 'woocommerce_sale_badge_text', 'custom_sale_percentage_badge', 10, 2 );

function custom_sale_percentage_badge( $sale_text, $product ) {

    if ( $product->is_type( 'simple' ) ) {
        $regular = (float) $product->get_regular_price();
        $sale = (float) $product->get_sale_price();

        if ( $regular > 0 && $sale > 0 ) {
            $percentage = round( ( ( $regular - $sale ) / $regular ) * 100 );
            return '-' . $percentage . '%';
        }
    }

    if ( $product->is_type( 'variable' ) ) {
        $max_regular = max( $product->get_variation_regular_price( 'max', true ) );
        $max_sale = max( $product->get_variation_sale_price( 'max', true ) );

        if ( $max_regular > 0 && $max_sale > 0 ) {
            $percentage = round( ( ( $max_regular - $max_sale ) / $max_regular ) * 100 );
            return '-' . $percentage . '%';
        }
    }
	
    return $sale_text;
}