Round Percentage Coupon Discounts in WooCommerce

A percentage coupon in WooCommerce often produces a discount with cents, such as 12.35 off. If you would rather give whole-number discounts, this filter rounds the coupon discount up to the next whole unit of your currency.

Add it to your child theme’s functions.php file.

add_filter( 'woocommerce_coupon_get_discount_amount', 'filter_woocommerce_coupon_get_discount_amount', 10, 5 );
function filter_woocommerce_coupon_get_discount_amount( $discount, $discounting_amount, $cart_item, $single, $instance ) {
    // Round the discount for all other coupon types than 'fixed_cart'
    if( ! $instance->is_type('fixed_cart') )
        $discount = ceil( $discount );

    return $discount; 
}

How it works

• woocommerce_coupon_get_discount_amount lets you change the discount WooCommerce calculated for a coupon. It passes five values; the last one, $instance, is the coupon object.
• is_type('fixed_cart') skips fixed cart coupons, whose amount is split across the cart items. Percentage and fixed product coupons are rounded.
• ceil() always rounds up, so 12.10 becomes 13 and the customer gets slightly more off. Use round() for the nearest whole number or floor() to always round down.
• The filter receives one cart item at a time ($cart_item), so each item’s discount is rounded separately. With several items in the cart, the total discount can end up a little higher than rounding the order’s discount once.

Test a few carts with different products and quantities before you go live, and clear any page cache afterwards.

Coupon and pricing rules that go beyond the defaults are part of the custom WooCommerce work I take on.

Related articles

• showing the amount and percentage saved on sale products: tells shoppers what a discount is worth
• moving the coupon form above the checkout order table: where customers enter the code