# Formula Column

Formulas are currently only available as part of the Structure Early Access Program. If you wish to participate in this program, please contact our support team.

Formula columns allow you to perform calculations or comparisons based on issue fields and display those results in a column.

## Add a Formula Column

Start with adding a new column by clicking the + icon to the right of the column headings. Select **Formula...** as its type.

### Name Your Formula

Open the Formula editor by clicking the downward-pointing triangle next to the new column header.

In the **Name** field, give the column a meaningful name – something that expresses the purpose of your formula and will be easily recognized by yourself and anyone you might share it with.

## Formula

Enter your formula into the **Formula **field and assign any necessary variables.

See Formulas for more information.

### Full Screen

The initial sizing for the formula editor is rather small. If you need more space, click **Full-Screen** to expand the window.

## Options (Aggregation)

Select **Sum over sub-items** to have each row display an **aggregate total**, meaning the results for each row will be calculated as a sum of the values for that row and its sub-items.

When aggregation is enabled, you have a couple of options:

**Exclude duplicates**- If an item appears more than once in the structure, it's value will only be included once within the aggregate total.**After filtering**- When checked, filtered items will not be included in the aggregate total. If this is left unchecked, the values of those items will be included in the calculation, even though they are not visible in the structure.*Note: items filtered by a Filter Generator are always excluded.*

You can also use aggregate functions to accomplish the same thing - or to create custom aggregations.

**Sum over sub-items** doesn't work for all formulas. For example, string values usually cannot be added together.

However, Structure has no way of knowing what each value represents, so these options are always available. When selecting this option, be careful to verify that the calculated values will make sense.

## Format

The** Format** section allows you to customize the format of your results. The following options are available:

**General**- this default option will work for most formulas. If your results don't look right, try one of the others.**Number -**lets you specify the number of decimal places that will always be shown. The value will be rounded up to the least meaningful digit in this format.**Percentage**- treats the value as a ratio (0.0 = 0%, 1.0 = 100%) and adds a percent sign.**Date/Time**- displays the results as date/time and allows you to pick the appropriate format.**Duration**- displays duration values as days, hours and minutes.

Note that dates, times and durations are all numbers in the Expr language.

Unless you select an appropriate format, duration is represented as the number of milliseconds. Dates are represented as "Epoch milliseconds", the number of milliseconds between midnight January 1st, 1970 (GMT) and the specified date, not counting leap seconds. Negative values are allowed to represent earlier dates.

## Sorting by Calculated Value

You can sort by the values calculated in a formula column by clicking the column header.