Percentage Calculator
Every everyday percentage question on one page: percent of a number, what percent one number is of another, changes, increases and discounts. Answers appear as you type, with the working shown.
- Instant results
- Step-by-step working
- Excel formula
- No sign-up
Percentage of a number
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X is what percent of Y
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Percentage change
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Increase a number by a percentage
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Decrease a number by a percentage
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Find the whole from a percentage
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Percentage difference
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How much percent off?
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What is a percentage calculator?
A percentage expresses a number as a fraction of 100: 25% means 25 out of every 100. A percentage calculator does the arithmetic for common questions, such as finding 15% of a bill, working out what share of a budget has been spent, or measuring how much a price has changed. This calculator covers eight types of question. It shows the answer, a sentence you can quote, the calculation steps and the equivalent spreadsheet formula.
How to use Percentage Calculator
- Find the card that matches your question, such as “What is 15% of 200?” or “30 is what percent of 120?”.
- Type your numbers into the boxes. You can include commas, currency symbols or a % sign.
- Read the answer and the sentence below it. The coloured bar shows the proportion at a glance.
- Open “Show working” for the steps and a formula for Excel or Google Sheets, then copy what you need.
Percentage formulas at a glance
- Part = Percentage ÷ 100 × Whole
- 15% of 200 = 0.15 × 200 = 30.
- Percentage = Part ÷ Whole × 100
- 30 out of 120 = 0.25 × 100 = 25%.
- Change % = (New − Old) ÷ |Old| × 100
- From 80 to 100 = 20 ÷ 80 × 100 = +25%.
- Whole = Part ÷ (Percentage ÷ 100)
- 45 is 15% of 45 ÷ 0.15 = 300.
Why use this percentage calculator
- Answers as you typeNo Calculate button and no page reloads. Change any number and the result updates instantly.
- Shows the workingEvery answer comes with the steps and a plain-English sentence, so you can check it or copy it into homework and reports.
- Spreadsheet formula includedCopy the matching Excel or Google Sheets formula and reuse the calculation on a whole column.
- Private and ad-free workspaceNumbers are calculated on your device. Nothing you type is sent anywhere.
Common uses
- Shopping and tips. Work out 20% off, a 15% tip, or how much a 7% sales tax adds.
- School and exams. Turn 42 out of 50 into a percentage, or check homework step by step.
- Work and finance. Measure sales growth, budget share, commission or a pay rise.
- Health and fitness. Track the percentage of a goal reached or body-weight change.
Need a different calculation? Try the percentage calculator, discount calculator or percentage change calculator, or generate numbers with the random number generator.
Example: a restaurant bill
Your bill is $86.40 and you want to leave an 18% tip. In “Percentage of a number”, enter 18 and 86.40: the tip is $15.55. Then use “Increase a number by a percentage” with 86.40 and 18 to get the total of $101.95 in one step.
What to expect from the result
Results are rounded to four decimal places for display; the spreadsheet formula keeps full precision. Percentage change from a starting value of 0 is undefined. This calculator is for everyday maths and does not handle compound interest or tax rules.
Percentage Calculator questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 15% of 200 is 0.15 × 200 = 30. Use the first card on this page to get the answer instantly.
How do I work out what percentage one number is of another?
Divide the part by the whole and multiply by 100. For example, 30 out of 120 is 30 ÷ 120 × 100 = 25%.
How do I calculate percentage increase or decrease?
Subtract the old value from the new value, divide by the old value and multiply by 100. A positive result is an increase and a negative result is a decrease.
What is the difference between percent and percentage points?
Percentage points measure the gap between two percentages. A rate rising from 10% to 12% is up 2 percentage points, which is a 20% increase relative to 10%.
Can I use these formulas in Excel or Google Sheets?
Yes. Open “Show working” under any result and copy the formula. For percentage results, format the cell as a percentage.