What is custom column in Power Query?

Parthiban Kannan

Updated on February 9, 2026

< 1 min read

A custom column in Power Query is a new column created using a formula or expression.
It allows deriving values based on existing columns with conditional or arithmetic logic.
In my project, we created a “Profit” column using Revenue – Cost.
We also made a “High Value” flag: if Amount > 50000 then "Yes" else "No".
Custom columns can use text, numeric, date, or logical functions.
They appear in the Applied Steps pane and update automatically on refresh.
Helps create business-ready fields without modifying the source data.
Supports complex transformations not available through simple UI operations.
Reduces post-load calculations in Power BI visuals or measures.
So custom columns make datasets more analytical and user-ready.