Calculations involve, in one way or another, the use of text fields. You can perform a calculation using any field type, but if you want the results of your calculations reported on a form, you need to have a text field that either calculates the data and places the result in the field performing the calculation, or calculates data in another field type and sends the data to a text field.
1. Open the PDF in Nitro Pro.
2. On the Forms ribbon, click Text Field.
3. On the page, drag the pointer where you want the text field to appear.
4. Double-click on the field and under the Properties ribbon, name the field and set General and Appearance properties.
5. Select Options and click Alignment. Select Right from the pull-down menu to align the values right.
6. Open the Format properties, click Select format category, and then select Number from the drop down menu.
7. Click Decimal places and type the number of decimal places you want to report in the calculated field.
8. Open the Calculate properties, and select Value type and do one of the following:
9. Click the Select… button to open the Field Selection dialog box. Hold down the Control or Shift key and click each field you want to calculate.
10. Click OK.