**christine@modernsecretary.com**I have three drop down fields in my form (two under Software Requested and another under Hardware Requested) that I want to calculate at the bottom with a total. I have calculation values set up for each option in the fields, and the calculation works great...if they happen to want to choose a product from each drop down. If they do not choose something on one of the drop downs, the calculation doesn't work correctly. For example, if I just choose something from the QuickBooks dropdown, the calculation doesn't work.

I am wondering if I have to account for the blank line at the top in the calculations? Or if I just have my formula set up incorrectly - maybe add some brackets around the calculation?

- JotForm Support
**Kiran**Yes. You are right in assuming to consider the first blank option in the drop down boxes. Please add another 0 for each dropdown in the calculation values so that it should work as expected.

Additionally, please enable the option

*Wait for input before including the field in calculation*from the advanced options of Calculation wizard for the fields**SALES TAX 8%**and**TOTAL TO BE CHARGED**.This option need not to be checked for ORDER SUBTOTAL field since it waits for all dropdown boxes to be selected.

Hope this information helps. Thanks!