Percentage Calculator
%Use this Percentage Calculator to solve common percentage problems quickly and easily for shopping, money, schoolwork and everyday math.
What is X% of Y?
X is what percent of Y?
Percentage Increase or Decrease
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About the Creator
MyCruncher — Founded by Bobby Dues
MyCruncher provides free online calculators designed to make everyday calculations easier to understand and use.
Meet Bobby Dues →Free Percentage Calculator – Calculate Percentages, Increases and Decreases
Need to calculate a percentage quickly? The free MyCruncher Percentage Calculator helps solve common percentage problems for shopping, finances, schoolwork, business, and everyday mathematics.
Whether you're finding a percentage of a number, determining what percent one number represents of another, or calculating percentage increases and decreases, this tool makes percentage calculations easier.
MyCruncher includes three different percentage calculation tools on one convenient page.
How to Use the Percentage Calculator
The MyCruncher Percentage Calculator provides three calculation options for different types of percentage problems.
1. What Is X% of Y?
Use this section when you know a percentage and want to find that percentage of a number.
- Enter the percentage. Provide the percentage you want to calculate, such as 20.
- Enter the number. Provide the value the percentage applies to, such as 100.
- Click Calculate. The calculator displays the resulting amount.
For example, calculating 20% of 100 gives 20.
2. X Is What Percent of Y?
Use this section when you want to determine what percentage one number represents of another number.
- Enter the number. Provide the part you want to compare.
- Enter the total. Provide the total or reference amount.
- Click Calculate. The result shows the percentage relationship.
For example, 25 out of 100 equals 25%.
3. Percentage Increase or Decrease
Use this section to calculate the percentage change between an original number and a new number.
- Enter the original number. Start with the original or beginning value.
- Enter the new number. Provide the updated or ending value.
- Click Calculate. The calculator displays the percentage change.
A positive change from a positive starting value indicates an increase. A negative change indicates a decrease.
Use Reset All when you want to return the calculator inputs and results to their initial state.
How Do You Calculate a Percentage of a Number?
To find a percentage of a number, divide the percentage by 100 and multiply the result by the number.
This formula works for whole percentages and decimal percentages.
Percentage Calculation Example
Example: Suppose you want to calculate 20% of the number 100.
Step 1: Convert the Percentage
Divide 20 by 100 to convert the percentage into a decimal.
Step 2: Multiply by the Number
Multiply 100 by the decimal value.
Step 3: Review the Result
The result is 20.
This same method can be used for shopping discounts, interest calculations, taxes, tips, and many everyday percentage problems.
Percentage of a Number Chart
The following chart shows different percentages of the number 200.
| Percentage | Number | Result |
|---|---|---|
| 5% | 200 | 10 |
| 10% | 200 | 20 |
| 15% | 200 | 30 |
| 20% | 200 | 40 |
| 25% | 200 | 50 |
| 30% | 200 | 60 |
| 50% | 200 | 100 |
| 75% | 200 | 150 |
You can use this table as a quick reference when estimating common percentages.
How to Find What Percent One Number Is of Another
Sometimes you know two numbers but need to determine the percentage relationship between them.
To calculate this, divide the first number by the total, then multiply by 100.
What Percent Is 25 of 100?
Suppose you want to determine what percentage 25 represents of the number 100.
Multiply the result by 100 to convert it into a percentage.
Therefore, 25 represents 25% of 100.
What Percent Is 18 of 24?
Suppose a student answers 18 questions correctly on a 24-question assignment.
The student answered 75% of the questions correctly.
This calculation is useful for test scores, sales targets, survey results, and other comparisons.
Common Percentage Relationships
This table shows what percentage several numbers represent of a total of 200.
| Part | Total | Percentage |
|---|---|---|
| 10 | 200 | 5% |
| 25 | 200 | 12.5% |
| 50 | 200 | 25% |
| 75 | 200 | 37.5% |
| 100 | 200 | 50% |
| 150 | 200 | 75% |
| 200 | 200 | 100% |
How Do You Calculate Percentage Increase?
Percentage increase measures how much a value has grown compared with its original value.
Start by subtracting the original number from the new number.
Divide the difference by the original number, then multiply by 100.
For a positive original value, a positive result indicates an increase.
Percentage Increase Example
Example: Suppose an item originally costs $100 and the price increases to $125.
Step 1: Find the Difference
Step 2: Divide by the Original Value
Step 3: Convert to a Percentage
Final Result
The price increased by 25% compared with its original value.
How Do You Calculate Percentage Decrease?
Percentage decrease measures how much a value has fallen compared with its original value.
For positive starting values, use the same percentage change formula. A negative result indicates a decrease.
Percentage Decrease Example
Example: Suppose an item's price decreases from $200 to $150.
Step 1: Calculate the Difference
Step 2: Divide by the Original Price
Step 3: Convert to a Percentage
Final Result
The item decreased in price by 25% compared with its original price.
Percentage Increase and Decrease Chart
The following table shows several examples of percentage changes between original and new values.
| Original | New Value | Percentage Change |
|---|---|---|
| 100 | 125 | +25% |
| 100 | 80 | −20% |
| 80 | 100 | +25% |
| 125 | 100 | −20% |
| 150 | 120 | −20% |
| 200 | 250 | +25% |
| 100 | 100 | 0% |
Notice that an increase from 100 to 125 equals 25%, but a decrease from 125 back to 100 equals 20%.
This happens because percentage change is calculated relative to the original value for each individual comparison.
Percentage vs. Percentage Points
Percentage change and percentage-point change are related, but they are not the same.
For example, suppose an interest rate increases from 20% to 25%.
Percentage-Point Change
Subtract the old percentage from the new percentage.
Relative Percentage Change
Divide the five-point difference by the original 20%.
Therefore, an increase from 20% to 25% is an increase of 5 percentage points or a 25% relative increase.
This distinction is especially useful when comparing interest rates, survey results, business statistics, and financial percentages.
How to Convert Percentages to Decimals
Percent means "per hundred."
To convert a percentage to a decimal, divide the percentage by 100.
For example, 25% becomes 0.25.
| Percentage | Decimal | Fraction |
|---|---|---|
| 10% | 0.10 | 1/10 |
| 20% | 0.20 | 1/5 |
| 25% | 0.25 | 1/4 |
| 50% | 0.50 | 1/2 |
| 75% | 0.75 | 3/4 |
| 100% | 1.00 | 1 |
Understanding these conversions can make many percentage problems easier to calculate and understand.
Everyday Uses for a Percentage Calculator
Shopping Discounts
Calculate the savings on a discounted product or service.
For example, 15% of an $80 item is $12.
Subtracting the discount leaves a $68 sale price.
Sales Tax Calculations
Percentage calculations can help estimate sales tax on a taxable purchase.
For example, 7.5% of $150 equals $11.25.
Actual tax rules and taxable amounts vary by location.
Restaurant Tips
Calculate a gratuity as a percentage of a bill amount.
For example, 20% of a $60 restaurant bill equals $12.
School Grades
Determine the percentage of questions answered correctly on a test.
For example, 18 correct answers out of 24 equals 75%.
Business and Sales Growth
Compare the change in sales, revenue, expenses, or other business measurements.
For example, sales increasing from $10,000 to $12,000 represent a 20% increase.
Budgeting and Personal Finance
Calculate the percentage of income allocated to savings, housing, transportation, or other expenses.
For example, saving $600 from a $5,000 monthly income represents 12%.
Common Percentage Calculation Mistakes
- Using the wrong starting value. Percentage change should be based on the appropriate original value.
- Forgetting to divide by 100. When calculating a percentage of a number, convert the percentage to decimal form first.
- Confusing the part and total. When finding what percent one number is of another, the total belongs in the denominator.
- Adding consecutive percentages incorrectly. Two successive percentage changes are not always equivalent to adding the percentages together.
- Confusing percentage points with percent change. A change between two percentages can be expressed in different ways.
- Dividing by zero. A relative percentage calculation is undefined when its required denominator is zero.
- Ignoring rounding. Calculations involving money may need rounding to cents, depending on the specific situation.
Frequently Asked Questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply the result by the number.
For example, 20% of 100 equals 20.
What is 20% of 100?
Twenty percent of 100 equals 20.
What is 25% of 200?
Twenty-five percent of 200 equals 50.
What percent is 25 of 100?
Divide 25 by 100, then multiply by 100.
The result is 25%.
What percent is 18 out of 24?
Divide 18 by 24 and multiply by 100.
The result is 75%.
How do I calculate percentage increase?
Subtract the original value from the new value, divide by the original value, then multiply by 100.
For positive original values, a positive result indicates an increase.
How do I calculate percentage decrease?
Use the same percentage change formula.
For positive original values, a negative result indicates a decrease.
What is the percentage increase from 100 to 125?
The increase is 25%. The value increased by 25 compared with the original value of 100.
What is the percentage decrease from 200 to 150?
The decrease is 25%. The value dropped by 50 compared with the original value of 200.
What is the percentage change from 100 to 80?
The percentage change is −20%, representing a 20% decrease.
What does a 100% increase mean?
A 100% increase means the amount has doubled relative to its original positive value.
For example, 50 increasing to 100 is a 100% increase.
Can a percentage be greater than 100%?
Yes. A percentage can exceed 100% when the part is larger than the reference total or the increase exceeds the original amount.
For example, 200% of 50 equals 100.
What happens when the original value is zero?
A standard relative percentage change cannot be calculated using an original value of zero because division by zero is undefined.
The difference between the two numbers can still be calculated, but a conventional percentage change requires special interpretation.
What is the difference between percentage change and percentage points?
Percentage points measure the arithmetic difference between two percentages.
Relative percentage change compares that difference with the original percentage.
Is a 20% increase followed by a 20% decrease equal to the original value?
No. Starting with 100, a 20% increase produces 120.
Decreasing 120 by 20% gives 96, not 100.
Can I use the calculator for shopping discounts?
Yes. You can calculate a percentage of an item price to determine the discount amount.
Use the MyCruncher Discount Calculator when you also want the final discounted price.
Can I use percentages for financial calculations?
Yes. Percentages are used in interest rates, savings, budgets, taxes, loans, and many other financial calculations.
Can I calculate percentages with decimal numbers?
Yes. Percentage formulas work with decimal values as well as whole numbers.
Does the Percentage Calculator have multiple calculation tools?
Yes. MyCruncher includes percentage-of-a-number calculations, part-to-total percentage calculations, and percentage increase or decrease calculations.
Is the MyCruncher Percentage Calculator free?
Yes! The MyCruncher Percentage Calculator is free to use for solving common percentage problems.
Explore More Free Finance & Everyday Calculators
Need to calculate discounted shopping prices? Try the Discount Calculator to estimate savings and final sale prices.
Want to calculate the tip on a restaurant bill? Use the Tip Calculator to estimate gratuity, total cost, and equal bill splits.
Need to estimate sales tax on a purchase? Explore the Sales Tax Calculator for tax and purchase total calculations.
Interested in how percentage interest rates affect savings? Try the Compound Interest Calculator to explore hypothetical interest growth over time.
Want a free calculator for your own website? Visit the Free Calculator Embeds Library for available embeddable tools.
Discover more free finance, percentage, shopping, savings, and everyday calculators at MyCruncher.com .
Important: Percentage Calculator results are mathematical estimates based on the values entered. Rounding, incorrect inputs, and situation-specific rules may affect how results should be interpreted. For financial, tax, or other decisions, consider the full context rather than relying on percentage calculations alone.