Percentage formulas in Excel and Google Sheets
Copy a formula, check a worked example, and choose the right number format. These arithmetic formulas work in both Excel and Google Sheets.
Last updated November 9, 2026
For a percentage result, select the result cell and apply Percentage formatting. For a price or quantity, use Number or Currency. Formatting changes how a value is displayed; it does not change the value used in the calculation.
Find a percentage of a number
=A2*B2A2 = 200; B2 = 15% → 30
Enter 15% in B2, not 15. A percentage cell stores 15% as 0.15.
Cell format: Number. Check these numbers in the calculator.
Find what percent one number is of another
=A2/B2A2 = 30; B2 = 200 → 15%
A2 is the part and B2 is the whole. The formula returns 0.15; percentage formatting displays 15%.
Cell format: Percentage. Check these numbers in the calculator.
Calculate percentage change
=(B2-A2)/A2A2 = 80; B2 = 60 → −25%
Use this with a positive starting value in A2. Negative means a decrease. Do not multiply by 100 if you also apply percentage formatting.
Cell format: Percentage. Check these numbers in the calculator.
Increase a value by a percentage
=A2*(1+B2)A2 = 200; B2 = 15% → 230
The 1 keeps the original amount; B2 adds the increase.
Cell format: Number or Currency. Check these numbers in the calculator.
Apply a percentage discount
=A2*(1-B2)A2 = 80; B2 = 25% → 60
This returns the amount you pay. The saving alone is =A2*B2.
Cell format: Number or Currency. Check these numbers in the calculator.
Find the original price before a discount
=A2/(1-B2)A2 = 60; B2 = 25% → 80
A2 is the sale price. This cannot recover an original price from a 100% discount because it would divide by zero.
Cell format: Number or Currency. Check these numbers in the calculator.
Calculate a grade percentage
=A2/B2A2 = 43; B2 = 50 → 86%
A2 is points earned; B2 is points available. Letter grades depend on your school's policy.
Cell format: Percentage. Check these numbers in the calculator.
Copy a percentage-of-total formula down a column
If A2 through A5 contain 20, 30, 10 and 40, enter =SUM(A2:A5) in A6. In B2, use =A2/$A$6 and format B2 as a percentage. Fill down to B5. The dollar signs keep the total fixed while A2 changes to A3, A4 and A5. The results are 20%, 30%, 10% and 40%.
Percentage points and percentage change
If A2 is 4% and B2 is 5%, =(B2-A2)*100, formatted as a Number, gives a difference of 1 percentage point. =(B2-A2)/A2, formatted as Percentage, gives a relative increase of 25%. Label the result so readers know which comparison you used.
Zero and negative starting values
A change from zero is undefined. Keep the division error visible or use a clearly labeled blank; replacing it with 0% falsely reports no change. Negative starting values require a stated convention. Our calculator divides by the starting magnitude: =(B2-A2)/ABS(A2). From −50 to −25 that gives +50%. Some financial reports instead mark these comparisons as not meaningful.
Why does my cell show 1500%?
You probably entered 15 and then applied percentage formatting. The stored number 15 represents 1500%. Enter 15% or 0.15 instead. Similarly, if =A2/B2*100 returns 15, applying percentage formatting will display 1500%. Remove the multiplication by 100.
Practice and references
Print our practice worksheet with worked answers, or use the batch percent-change calculator to compare multiple rows and download a CSV.
Reference: Microsoft's percentage examples and Google's TO_PERCENT documentation. Function names and argument separators can vary with spreadsheet language settings; the basic arithmetic examples above use operators shared by both products.