Adding Tax

The Total Field cannot be used in calculations. Because the Total would be impacted by the results of that calculation and used in the calculation itself... you'd get into an infinite loop situation. So it isn't something that is supported.

David is correct. The only way to do this is to use a Product Field configured as a Calculation and to configure a formula that both calculates a total and multiplies it by the tax percentage.

Gravity Forms Pricing Fields are designed for basic order forms. It does not have built in functionality for more complex ecommerce operations. It does not currently have any Tax functionality as it's primarily designed for situations where taxes are incorporated into the cost of what is being sold. Which is common when purchasing tickets to events, purchasing digital downloads, etc.

We get asked frequently how we could possibly leave Taxes out but what people don't realize is Taxes are much more complex than they sound. As our product is used by people all over the world any Tax functionality we would implement would need to take this into account. Which means supporting a wide variety of tax scenarios as well as multiple taxes. State, city, county, vat, etc. It's much more complex than it sounds and it's outside the scope of what Gravity Forms does.

With that many products involved a shopping cart style solution may have been the more appropriate route to take. That's a lot of products to incorporate on a single form.