This plugin rounds off Woocommerce Cart Total to nearest 5 cents (or nearest 5 in the 2nd decimal for any currency).

Swiss 5-cent Rounding allows you to easily apply rounding to the nearest 0.05 interval for discount and VAT amounts in your WooCommerce shop.

Rounds the WooCommerce cart and order total to 5 Swiss centimes (0.05 CHF) with a visible, VAT-free rounding line.