Using this field type you can calculate value by formula.

**There are several ways how it can be used:**

- Simple use values from other fields
- Use PHP math function in formula
- Use PHP code to calculate value

**1. Simple use values from other fields**

Just for example for Projects you have to have field Profit where Income-Expenses = Profit

Filed Income have ID 99

Field Expenses have ID 100

Then formula for field Profit will be:** [99]-[100]**

Numbers in [] are fields ID and they will be replaced by field values.

Value of formula field will be calculated automatically in projects listing and project info page

**2. Use PHP math function in formula**

Also in formula you can use any PHP math functions.

For example formula string can be: **max([99],[100])
**So field will display highest value from fields 99 and 100

See all math functions here http://www.php.net/manual/en/ref.math.php

**3. Use PHP code to calculate value**

For example formula can be:

([100]>1100 ? [100]/2 : [99])