Custom Calculation Script for Fillable Forms - PDFs

[Brandi Fuller]

I am working on creating a form in which I need to calculate ship profit. My fields are as follows:

• Our Cost
• Customer Price
• Surcharge
• Subtotal (Customer Price + Surcharge)
• Ship Profit

Here is the formula in plain english.  Can someone help me write the custom calculation please?

Subtotal - Our Cost/Subtotal

I need this to be a precentage, so I don't know if it then should be:

Subtotal minus Our Cost divided by Subtotal minus 1.

Thank you in advance for your help!  Below is a screen shot of my form as is.  

[Nesa Nurani]

1. Did you format "Ship Profit" field as percentage?

2. You want to show profit as percentage compared to "Our Cost"? Let's say "Our Cost" is 100 and "Subtotal" is 150 you want "Ship Profit" to show as 50%?