Shows a message at the WooCommerce cart/checkout displaying how much customer needs to add to get free shipping. Only shows if there are items in cart

functions.php

/**
 * Show a message at the cart/checkout displaying
 * how much to go for free shipping.
 */
function wc_free_shipping_incentive_notice() {


	if ( ! is_cart() && ! is_checkout() && ( WC()->cart->get_cart_contents_count() == 0 ) ) {
		return;
	}

	$packages = WC()->cart->get_shipping_packages();
	$package = reset( $packages );
	$zone = wc_get_shipping_zone( $package );
	$current = WC()->cart->subtotal;
	$cart_total = WC()->cart->get_displayed_subtotal();

	if ( WC()->cart->display_prices_including_tax() ) {
		$cart_total = round( $cart_total - ( WC()->cart->get_discount_total() + WC()->cart->get_discount_tax() ), wc_get_price_decimals() );
	}

	else {
		$cart_total = round( $cart_total - WC()->cart->get_discount_total(), wc_get_price_decimals() );
	}

	foreach ( $zone->get_shipping_methods( true ) as $k => $method ) {
		$min_amount = $method->get_option( 'min_amount' );


	   if ( $current < $min_amount ) {
	      $added_text = 'Get free shipping if you order ' . wc_price( $min_amount - $current ) . ' more!';
	      $return_to = wc_get_page_permalink( 'shop' );
	      $notice = sprintf( '<a href="%s" class="button wc-forward">%s</a> %s', esc_url( $return_to ), 'Continue Shopping', $added_text );
	      wc_print_notice( $notice, 'notice' );
	   }
	}


}
add_action( 'woocommerce_before_cart', 'wc_free_shipping_incentive_notice' );