Percentage Calculator
The Percentage Calculator helps you find percentages, percentage amounts, and the relationship between values. Percentages are used throughout everyday calculations, including discounts, increases, test scores, budgets, statistics, business figures, and financial comparisons.
How to use this calculator
- Enter the values requested by the calculator for the percentage calculation you want to perform.
- Check that the numbers represent the same type of quantity and use compatible units.
- Review the calculated percentage or percentage amount.
- Use the result together with the original values so that the percentage has the correct context.
Basic percentage formula
Percentage = (Part ÷ Whole) × 100
- A percentage expresses a quantity as a proportion of 100.
- The part is divided by the whole to determine the proportion, then multiplied by 100 to express that proportion as a percentage.
- When finding a percentage amount from a known percentage, the percentage is first converted into a decimal and then multiplied by the relevant value.
Worked examples
Example: finding a percentage
Suppose 30 students are present in a group of 40.
(30 ÷ 40) × 100 = 75%
30 is 75% of 40.
Example: finding a percentage amount
Suppose you want to find 15% of 200.
200 × 0.15 = 30
15% of 200 is 30.
Understanding the result
A percentage is a ratio expressed relative to 100. This makes it useful for comparing proportions even when the original quantities are different.
The whole or reference value matters. Saying that a value is 20% of something only has meaning when the reference quantity is known.
Percentage calculations can represent increases, decreases, proportions, rates, or shares depending on how the values are defined.
Important notes
Make sure you identify the correct whole or reference value before calculating a percentage.
Do not confuse a percentage with a percentage-point difference when comparing two percentages.
Round results appropriately for the purpose of the calculation rather than assuming every result should be rounded to a whole percentage.
Frequently asked questions
What does percent mean?
Percent means “per hundred.” A value of 25% represents 25 parts out of 100.
How do I calculate what percentage one number is of another?
Divide the first number by the reference number and multiply the result by 100.
How do I turn a percentage into a decimal?
Divide the percentage by 100. For example, 25% becomes 0.25.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
- How to Calculate Percentage Change — Learn the percentage change formula, how to calculate increases and decreases, and why the original value matters.
- Percentage Change vs Percentage Difference — Understand the difference between percentage change and percentage difference, including when each formula is appropriate.
- Percentage Change — Learn what percentage change means, how to calculate increases and decreases, and how the original value affects the result.
This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.