WooCommerce Ajax Cart Plugin

WooCommerce AJAX Cart is a WordPress Plugin that changes the default behavior of WooCommerte Cart Page, allowing a buyer to see the Total price calculation when change the Quantity of a product, without need to manually click on "Update cart" button.

This improves the user experience when purchasing a product. No other hacks/code/theme changes is needed, this functionality is added when the plugin is activated.

You can try and play with this plugin demonstration clicking here

Free version features:

• Automatically reload and recalculate Cart using AJAX when quantity changes
• Show -/+ buttons around item quantity on cart page
• Show item quantity as select instead numeric field
• Show user confirmation when change item quantity to zero

Premium version features:

• Allow to change/synchronize quantities in shop, minicart and single product pages view demo
• Make the Add to cart button to perform with AJAX, without full page reload view demo
• Faster AJAX reload call when change quantities in Cart page
• Option to lock quantity inputs to allow only change using plus and minus buttons
• Update price vs quantity calculation automatically on Single Product pages

If you looking for a related plugin with more complete features maybe you can try WooCommerce Better Usability plugin.