Percentage Calculator FAQs
Short answers with a link to the calculator or guide that does the work. Use the cards to jump by topic, or scan the questions below. Long how-to articles live on the learn pages, not here.
How do I calculate…
Core arithmetic. Each card opens the tool for that formula.
Which words mean which formula?
Nearby terms that are easy to mix up.
Learn and practice
Methods, formula sheets, and the three existing games.
Divide the percent by 100 and multiply by the number. 15% of 80 is 12.
Divide the first number by the second and multiply by 100. 25 is 12.5% of 200.
Change divides by a starting value and can be positive or negative. Difference divides by the average of the two numbers and is symmetric.
- 50 to 65 is a 30% increase (change).
- 80 and 100 differ by 22.222% (difference).
Divide the final amount by 1 plus the rate after an increase, or by 1 minus the rate after a decrease. 110 after a 10% increase came from 100.
Sale price is original × (1 − discount / 100). 15% off 200 is 170, with 30 saved.
Markup divides profit by cost. Margin divides profit by selling price. Cost 100 and price 150 is a 50% markup and a 33.333% margin.
No. 90% is a score out of 100. The 90th percentile is a rank in a group of scores.
Percentage points are the additive gap between two percents. A move from 10% to 12% is 2 percentage points, which is a 20% increase of the original rate.
Use cell formulas. Percent of a number is =A1*B1/100. What percent is =(A1/B1)*100. Percentage change is =(B1-A1)/A1.
- Format the result as a number if you already multiplied by 100.
- Or write =A1/B1 and format the cell as a percent.
Yes. Percentage is a free offline calculator for iPhone and iPad: discounts, tax, tips, marks, and practice. No ads, no account, and no internet required.
Yes. The same Percentage calculator is also on Google Play: offline, no ads, no account.