In Productive, there is a column for just about everything, but sometimes you have your unique metric or calculation that isn't available by default.

Luckily, **you can use formulas to merge multiple columns into a custom column with simple mathematical operations.**

To add your custom column,** click on** **Columns** > **Add Formula Column**.

First, start by giving your new column a name:

Now it's time to add the values you would like to use. To select the first value, **type in the "@" symbol **- it will show a drop-down menu with a list of available values:

**Select the values** you would like to use and combine them as a formula. The following operations are supported:

**Addition ( + )****Subtraction ( - )****Multiplication ( * )****Division ( / )**

You can also put your formula in **brackets**: *( A + B) - C *

In this example, we'll create a column that will display the difference between total and remaining budget. The formula used is **Budget total** *(minus)* **Budget used.**

When finished, **click on Create Column**.

Now, the column is visible in the main view:

Formula columns are available for all **numeric** data across Productive.

## Composite Formulas

You can create a composite formula, one that is made of other formulas. For example, the column Time Worked is made out of two formulas:

You can use that formula to compose other formulas as well: