Percentage Calculator
Use this percentage calculator to find a percent of a number, see what percent one number is of another, or measure an increase or decrease. The three widgets below answer those questions at once. Dedicated pages cover discounts, marks, win percentage, time, reverse percentage, and more, and each core skill has a matching percentage calculator game.
What a percentage calculator does
A percentage is a part of 100. A percentage calculator turns that idea into a number you can use: a tip, a sale price, a test score, a win rate, or a change from last month.
Almost every percentage question is one of three moves. You start with a percent and a whole and find the part. You start with a part and a whole and find the percent. Or you compare an old value with a new value and find the change.
The widgets on this page run those three moves. The rest of the site applies the same math with the labels people search for, such as discount, marks percentage, win percentage, and percentage of time.
The three core percentage formulas
Learn these three lines and you can solve most everyday percentage problems by hand or check any calculator result.
| Question | Formula | Example |
|---|---|---|
| What is X% of Y? | (X / 100) × Y | 15% of 80 = 12 |
| X is what % of Y? | (X / Y) × 100 | 25 of 200 = 12.5% |
| Change from A to B | ((B - A) / A) × 100 | 50 to 65 = 30% |
How to choose the right percentage tool
Match the tool to the words in your question. The formula stays simple. The labels change.
- Percent of a number: tips, tax on a subtotal, commission, or any "what is X% of Y" question.
- What percent: scores, budgets, and "X out of Y as a percent".
- Percentage change: growth, decline, raises, and price moves from a clear starting value.
- Percentage difference: compare two numbers when neither is the baseline.
- Reverse percentage: recover the original amount before a percent was added or taken off.
- Discount, markup, and margin: shopping and pricing labels on top of the same core math.
- Marks, attendance, win percentage, and percentage of time: school and stats rates with ready-made fields.
Percentage calculator games
Practice locks the formulas in. The games hub runs timed rounds for percent of a number, what percent, and percentage increase, plus a 60-second sprint, a matching board, and a sale-price run.
Open a calculator when you want the worked line, then return to a game and answer the same question under a clock.
Common percentage entities people mix up
Nearby words sound alike and measure different things. Use the right page so the answer matches the question.
- Percent vs percentage points: a move from 10% to 12% is 2 percentage points and a 20% relative increase.
- Percentage vs percentile: 90% is a share of a whole. The 90th percentile is a rank in a list.
- Markup vs margin: markup divides profit by cost. Margin divides profit by selling price.
- Percentage change vs percentage difference: change needs a starting value and has a direction. Difference uses the average of both numbers.
- Winning percentage: a win rate from wins, losses, and optional ties, not a generic part-over-whole until you form the games total.
Worked examples you can check by hand
Use these as a quick accuracy check against the widgets above or any dedicated tool.
- 15% of 200 is 30. Sale price at 15% off is 170.
- 45 marks out of 60 is 75%.
- 8 wins and 2 losses is an 80% win percentage.
- 30 minutes of 2 hours is 25% of the time.
- A price that became 170 after 15% off started at 200. That is reverse percentage.
- Rates of 70%, 80%, and 90% average to 80% when each carries equal weight.
All percentage tools
The homepage widgets cover the three most common questions. Open a dedicated page when you need shopping labels, school or sports rates, reverse percentage, or a worked example.
Core tools
Shopping and money
School and stats
Games and guides
The three core formulas
Most percentage questions are one of these three. Open the matching calculator for a worked line, or read the full method on the how-to guide.
Percentage change
((new - original) / original) × 100. 50 to 65 is a 30% increase.
Step-by-step method
Worked examples for all three operations, plus when to use reverse percentage instead.
Everyday percentage tasks
Shopping, school, and sports use the same core math with different labels. Open the tool that matches the words you already have.
Discounts and reverse percentage
Take a percent off a price, find the discount percent, or recover the original amount before the percent.
Marks and attendance
Turn marks obtained over total marks into a percent, or days present over working days.
Win percentage and time
Build a win rate from a win-loss record, or turn minutes and hours into a percent of a longer period.
Percentage calculator questions
A percentage calculator finds a percent of a number, turns a part into a percent of a whole, or measures change between two values. This page runs those three operations, then links to specialized tools for discounts, marks, win percentage, and more.
Divide the percent by 100 and multiply by the number. 15% of 80 is 0.15 × 80 = 12. Use the first widget above or the dedicated percent-of page.
Divide the part by the whole and multiply by 100. 25 is 12.5% of 200.
No. Change uses a starting value and can be an increase or a decrease. Difference uses the average of the two numbers and has no direction.
Divide the final amount by (1 ± percent/100), matching whether the percent was added or taken off. A sale price of 170 after 15% off started at 200.
Use the win percentage calculator for wins, losses, and ties. Use marks percentage for score over total marks. Both sit under School and stats on this page.
Yes. Six short games cover percent of a number, what percent, percentage increase, a 60-second sprint, matching pairs, and sale prices.
Yes. Percentage is a free offline calculator for iPhone, iPad, and Android: discounts, tax, tips, marks, and practice. No ads, no account, and no internet required.