**What is a calculation field?**

A calculation field is a new field type for your post-its. It enables you to calculate a value from a formula using existing variables.

Variable are values of the document, it can be :

- A document formula (see : Document formulas).
- A post-it field of the document (numeric, duration or calculation), either :
- Field value on the post-it
- Average of field value of all document post-its
- Sum of field value of all document post-its

**Create a calculation field**

To create a new calculation field, click on the icon **"Settings"** in the document toolbar, then within the extended fields part, click on **"Edit list"**.

The list of the fields assigned to post-its in the document opens. In the **"Add"** field, type in a name for the new field, select **"Calculation"** type and click on "**Create**".

The field configuration windows opens :

In the "Formula" field, define the calculation wanted : you can use numeric values, basic operators (+, -, *, /, (, ) ) and variables of your document.

To call a variable, use the @ key on your keyboard and choose the wanted variable in the list.

For a document formula variable, you can directly use the value.

For a post-it field variable, you can choose to use the field value on the post-it, the average or the sum function (of field values for every post-its of the document).

Finally, for the duration field variable, you will have to define a time unit ot use in the calculation (for example : you typed in an average of 2 days in the values of field "A" and you specified a variable "Avg(A)" in hours, then the value used for calculation will be 48 (2 days * 24hours)).

**Use calculation fields**

The value of the calculation field on each post-it is automatically calculated, you cannot edit this value directly on the post-it.

The calculation field value is displayed as any other field values on the post-its.