Google Sheets Percentage Calculator & Formula Builder
Quick answer: Percent change in Google Sheets is =(B1-A1)/A1 (format the cell as %); B1 as a percent of a total A1 is =B1/A1; increase A1 by B1 percent is =A1*(1+B1).
Enter an old and a new value to see the percentage change instantly, or build the exact formula for your cells — percent change, percent of total, increase, decrease, or add tax/markup — and copy it in one click.
Instant percentage change
Type an old value and a new value — get the percentage change straight away, no formula needed.
Build the Google Sheets formula
Point it at your cells, pick the calculation, copy the formula.
=(B1-A1)/A1
How this percentage calculator works
A percentage is just a ratio. To find how much a value changed, subtract the old value from the new one and divide by the old value: =(B1-A1)/A1. The result is a decimal (0.25), so format the cell as a percentage to show 25%%.
To express one number as a percent of another (part ÷ whole), use =B1/A1. To grow a number by a percent stored as a decimal, multiply by one plus that percent: =A1*(1+B1); to shrink it, use 1-B1. If you want the % sign baked into text instead of relying on cell formatting, wrap the result in =TEXT(..., "0.0%%").
Common ready-to-paste examples
Percentage change from A1 to B1:
=(B1-A1)/A1
B1 as a percentage of total in A1:
=B1/A1
Increase A1 by the percent in B1:
=A1*(1+B1)
Decrease A1 by the percent in B1:
=A1*(1-B1)
Show the change as formatted % text:
=TEXT((B1-A1)/A1, "0.0%")
FAQ
What is the formula for percentage change in Google Sheets?
Use =(new-old)/old, e.g. =(B1-A1)/A1, then format the cell as a percentage. A positive result is an increase, a negative one is a decrease.
How do I calculate a percentage of a total in Google Sheets?
Divide the part by the whole: =B1/A1. Format the cell as a percentage, or wrap it in TEXT(B1/A1,"0.0%") to show the % sign as text.
How do I increase or decrease a number by a percentage?
To increase A1 by the percent in B1 use =A1*(1+B1); to decrease use =A1*(1-B1). Store the percent as a decimal (10% = 0.1) or format B1 as a percentage.
Why does my percentage show as 0.25 instead of 25%?
Google Sheets stores percentages as decimals. Select the cell and click the % button in the toolbar, or use Format > Number > Percent, to display 0.25 as 25%.