The basics

Keep one cell fixed when copying (the $ sign)

How it works in Excel

• B2 has no $ signs, so it moves as you copy down.
• $E$1 is locked, so it always points to E1.
• Press F4 while on a reference to add the $ signs.
• $E1 locks only the column, and E$1 locks only the row.

The idea in general

Some parts of a calculation change on each row and some stay put, like a price per item and a single tax rate.

What I assumed

• The changing numbers are in column B and the fixed number is in E1.

Check the result on your own data before relying on it.