**sparkanddelight**I'm creating an order form for people to buy wedding invitation suites, where each part of the suite can be purchased individually. To make it work on a sliding scale, The number of invitations has a calculation value equal to the total for purchasing an entire suite, and then each part is assigned a percentage of that total. For instance.

25 Invitations has a calculation value of 350. The invitation calculation then multiplies 350 x 40% to return $140 for 25 invitations, and so on.

It works great, except there are two options that are not based on percentage points that need to be calculated agains the actual number of invitations. Is it possible to build a calculation from the actual field values instead of the assigned calculation values?

My form is here:

http://form.jotform.us/form/52585917089167?

The calculations in question are the Mailing services. Currently I have an additional field where they select the number of invitations a second time, which I would like to eliminate if possible.

**sparkanddelight**I was able to solve this by passing the value of the invitation field to a hidden field, reversing the calculated values for the hidden field and using the hidden field in the calculation for the non-percentage fields.

**Charlie**Hi,

I cloned your form but I'm unable to see the reverse calculation to make the quantity invitation to be in an input field. Have you already resolved this?

One possible way for this is that I can think of is using conditional logic to insert a specific quantity invitation to the hidden field. Unfortunately, this might take time to setup, here's a sample:

1. I changed the hidden "Total Number of Invitations" to a text box to handle a number

2. In the conditional logic, this is how I set it up.

3. You can see how it works here: http://form.jotformpro.com/form/52594911669973.

I hope that helps.

**sparkanddelight**Thanks. Yeah I was able to easily solve it by just reversing the calculation values in the hidden field.

so if the Invite field says 25, the calculation value is 350.

I added the Hidden field and auto-populated it from the Invitation field. So it auto-populates to 350.

Then I assigned new calculation values to the hidden field in reverse. so if the field auto-populates to 350 and the calculation value is 25, and so forth. then I used the hidden field in the calculation for the last two fields. I don't know if that makes sense, but in short it solved my problem.

Thanks for the response!

- JotForm Support
**Welvin**That's great to know!

Please contact us again if we can help in any way.

Thanks