Google announced in a Google+ update that Custom Columns in AdWords now supports custom formulas.
Google first launched Custom Columns in late 2014 as a way to let advertisers segment column metrics based on their goals.
The AdWords page says:
Custom columns lets you easily create and view segmented columns for the metrics you want to see in AdWords. To make custom columns more useful for your business needs and save you time, you’ll soon be able to do quick computations like addition, subtraction and multiplication -- right from your AdWords custom columns.
Now when you create custom columns, in addition to specifying custom segmentations for your metrics, you can apply formulas for those metrics. For example, to see the percentage of clicks you get from mobile devices, create a custom column that divides mobile clicks by total clicks. Or let's say you’re a shoe retailer and enjoy a 40% profit margin for each pair of shoes you sell. To understand your total profit for each sale, ensure your conversion value column tracks revenue. Then, create a custom column that multiplies conversion value by 40% and call it “Estimated Profit.” As always, you can still sort, chart, filter and download your custom columns, as well as include them in reports and automated rules.
Google has a help center section detailing the use of custom columns, including a twelve-step guide to setting them up.
Image via AdWords