Learn how to add Availability label ? in your WooCommerce website. This will help to notify customers how many products are available or if the product is stock out.

add_filter( 'woocommerce_cart_item_price', 'filter_cart_item_price', 10, 3 );

function filter_cart_item_price( $price_html, $cart_item, $cart_item_key ) {

    if( $cart_item['data']->is_on_sale() ) {

        return $cart_item['data']->get_price_html();

    }

    return $price_html;

}

add_filter( 'woocommerce_cart_item_subtotal', 'filter_cart_item_subtotal', 10, 3 );

function filter_cart_item_subtotal( $subtotal_html, $cart_item, $cart_item_key ){

    $product    = $cart_item['data'];

    $quantity   = $cart_item['quantity'];

    $tax_string = '';

    if ( $product->is_taxable() ) {

        if ( WC()->cart->display_prices_including_tax() ) {

            $regular_price = wc_get_price_including_tax( $product, array( 'qty' => $quantity, 'price' => $product->get_regular_price() ) );

            $active_price  = wc_get_price_including_tax( $product, array( 'qty' => $quantity ) );

            if ( ! wc_prices_include_tax() && WC()->cart->get_subtotal_tax() > 0 ) {

                $tax_string = ' <small class="tax_label">' . WC()->countries->inc_tax_or_vat() . '</small>';

            }

        } else {

            $regular_price = wc_get_price_excluding_tax( $product, array( 'qty' => $quantity, 'price' => $product->get_regular_price() ) );

            $row_price     = wc_get_price_excluding_tax( $product, array( 'qty' => $quantity ) );

            if ( wc_prices_include_tax() && WC()->cart->get_subtotal_tax() > 0 ) {

                $tax_string = ' <small class="tax_label">' . WC()->countries->ex_tax_or_vat() . '</small>';

            }

        }

    } else {

        $regular_price = $product->get_regular_price() * $quantity;

        $active_price  = $product->get_price() * $quantity;

    }

    if( $product->is_on_sale() ) {

        return wc_format_sale_price( $regular_price, $active_price ) . $product->get_price_suffix() . $tax_string;

    }

    return $subtotal_html;

}