How to Apply Bulk Quantity Discount (Buy 10 Get 1 Free) in WooCommerce?

In an online store, having just great products isn’t enough—it demands smart sales strategies to stand out. With a “Buy 10 Get 1 Free” promotion in WooCommerce, you can simply boost your store’s average order value. For instance, when customers buy 10 boxes of coffee pods, they get 1 box for free. This helps you clear stocks quickly and customers also feel that their purchase is valuable as they get a bonus when purchased in bulk.

Solution: Apply Bulk Quantity Discount (Buy 10 Get 1 Free) in WooCommerce

This guide focuses on the implementation of a BOGO-like discount, where customers receive a 100% discount after purchasing a specified quantity that applies well for both simple and variable products.

add_action('woocommerce_cart_calculate_fees', 'ts_add_custom_discount_11th_at_100', 10, 1 );

function ts_add_custom_discount_11th_at_100( $wc_cart ){
    if ( is_admin() && ! defined( 'DOING_AJAX' ) ) return;

    $discount = 0;
    $items_prices = array();

    // Set HERE your targeted product ID
    $targeted_product_id = 396;

    foreach ( $wc_cart->get_cart() as $key => $cart_item ) {
        $product_id = $cart_item['product_id'];
        $qty = intval( $cart_item['quantity'] );

        // Use the correct method to get the product object
        $product = $cart_item['data'];

        // Get the product price, considering variable products
        $price = $product->is_type('variable') ? $product->get_price() : $product->get_price($qty);

        for ( $i = 0; $i < $qty; $i++ ) {
            $items_prices[] = floatval( $price );
        }
    }

    $count_items_prices = count($items_prices);

    if( $count_items_prices > 10 ) {
        foreach( $items_prices as $key => $price ) {
            if( $key % 11 == 1 ) {
                $discount -= number_format($price / 1, 11 );
            }
        }
    }

    if( $discount != 0 ){
        // Displaying a custom notice (optional)
        wc_clear_notices();
        wc_add_notice( __("Buy 10 Get 1 Free"), 'notice');

        // The discount
        $wc_cart->add_fee( 'Buy 10 Get 1 Free', $discount, true  );
        # Note: Last argument in add_fee() method is related to applying the tax or not to the discount (true or false)
    }
}

Output

When the customer adds the targeted product ID set in the code to the cart and continues to add the same product (ID 396) to the cart, reaching a total quantity of 10. Upon adding the 11th product, the code implies offering a 100% discount to that 11th product.

Also, you can explore an easy way to provide WooCommerce bulk quantity-tiered discounts based on the based on the total quantity of the items present in the cart.