Copy the formula for your question
Each row below is an independent example. Enter the stated inputs in A2 and B2, then place the formula in C2. Format C2 as Percentage only when the result itself is a rate.
| Task | Example inputs | Formula for C2 | Result | C2 format |
|---|---|---|---|---|
| Percentage of an amount | A2 = 200; B2 = 15% | =A2*B2 |
30 | Number |
| Part of a total | A2 = 30; B2 = 200 | =A2/B2 |
15% | Percentage |
| Percentage change | A2 = 80; B2 = 100 | =(B2-A2)/A2 |
25% | Percentage |
| Price after discount | A2 = 200; B2 = 15% | =A2*(1-B2) |
170 | Number |
| Amount after increase | A2 = 200; B2 = 15% | =A2*(1+B2) |
230 | Number |
| Original before discount | A2 = 800; B2 = 20% | =A2/(1-B2) |
1,000 | Number |
| Whole from a known part | A2 = 30; B2 = 15% | =A2/B2 |
200 | Number |
Why 15% and 15 give different answers
Excel stores 15% as 0.15. Multiplying 200 by 0.15 gives 30. Multiplying 200 by the plain number 15 gives 3,000.
If B2 contains 15%, use =A2*B2. If B2 contains the plain number 15, use =A2*B2/100. Dividing by 100 again when B2 already contains 15% makes the result 100 times too small.
For a part-to-total calculation such as =30/200, Excel returns 0.15. Apply the Percentage format from Home → Number to display 15%. Formatting changes the display, not the underlying value. Increasing or decreasing displayed decimals does not round the stored calculation.
Apply one percentage to a whole column
Suppose A2:A4 contains 200, 500 and 1,000, and B1 contains 15%. Enter this formula in B2, then fill down through B4:
=A2*$B$1The results are 30, 75 and 150. The dollar signs keep the reference to B1 fixed. The reference to A2 changes to A3 and A4 as you fill down. Without the dollar signs, the rate reference also moves.
To subtract the same rate from every amount, use =A2*(1-$B$1). To add it, use =A2*(1+$B$1).
What is inside the free workbook?
Examples: seven independent calculations with editable inputs, calculated answers, formula text and result-format guidance. Whole column: a single rate applied to a list, with percentage amounts, discounted values and increased values.
Amber cells are inputs. Rate cells accept values such as 15%; the sheet explains which inputs are amounts and which are rates. Blank or invalid required inputs display a message rather than a misleading zero. The file contains formulas and formatting, with no macros or external workbook links.
Fix common percentage formula problems
Why does the answer display as 1,500%?
A plain value of 15 displayed as a percentage becomes 1,500%. If you intend 15%, enter 15% or 0.15. Check the stored value and formula before changing the format.
Why do I get #DIV/0!?
Your formula divides by a zero or empty denominator. A part-to-total rate needs a non-zero total. Percentage change needs a valid original value. Do not replace every division error with zero: it can hide missing inputs.
Why does my formula change when I fill down?
Relative references move with the formula. Put dollar signs around a shared rate reference, such as $B$1, to keep it fixed. Leave the row reference to each amount relative.
How do I round the actual result?
Use =ROUND(A2*B2,2) to round a calculated amount to two decimal places. Percentage formatting only changes what is displayed. Depending on your regional Excel settings, function arguments may use semicolons instead of commas.
Check your spreadsheet result
The bulk percentage calculator applies one rate to a list without opening Excel. Use the formula cheat sheet to choose a method, or the fraction, decimal and percentage chart to check equivalent values.
References
Formula and formatting guidance: Microsoft: Calculate percentages and Microsoft: Multiply by a percentage in Excel. Examples and downloadable workbook are original to YourPercentageCalculator.com.