Percentage Change and Percentage of Total Formulas
TL;DR: Percentage change is (new - old) / old, formatted as a percentage: =(B2-A2)/A2. A negative result is a decrease. Use IFERROR when the old value can be zero.
Percentage change
=(New - Old) / Old
=(B2 - A2) / A2Format the cell as a percentage (Ctrl+Shift+% in Excel). If the old value can be zero, use =IFERROR((B2-A2)/A2, "").
Percentage of total
=B2 / SUM($B$2:$B$20)Lock the total with $ so it stays fixed when copied down.
Add or remove a percentage
- Add 20%:
=A2*(1+20%) - Remove 20%:
=A2*(1-20%) - Get the price before 20% tax was added:
=A2/1.2(not A2*0.8, a common mistake)
For sale prices, percent off, stacked discounts and multi-buy deals, see our discount formulas guide.
Percentage points vs percent
Going from 10% to 15% is a rise of 5 percentage points, but a 50% increase.