Introduction
Mixed references in Excel let you fix either the column or the row when copying formulas. This helps keep part of the formula constant while allowing the other part to change, saving time and avoiding errors.
When you want to copy a formula across columns but keep the row fixed, like applying a tax rate from a single row to many columns.
When you want to copy a formula down rows but keep the column fixed, such as multiplying each row's value by a fixed price in one column.
When creating multiplication tables where one axis stays constant and the other changes.
When referencing a header row or column that should not move as you copy formulas.
When you want to mix fixed and relative parts in a formula to adapt to different data layouts.