Seven calculation modes
Handle percent of, part-to-whole, change, adjustments, reverse percentages, symmetric difference, and percentage-point movement.
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Calculator · Free
Percentage Calculator
Solve percentage questions from every direction: find a percent, recover an original value, compare percentage points, and convert fractions or decimals.
Calculations stay in this browser
Calculation type
Percent of
What is X% of Y?
Result
50
20% of 250
Formula
20 ÷ 100 × 250
Quick percentages of 250
Conversion desk
Convert fractions, decimals, and percentages
Enter one form and see all three equivalent values immediately.
Use a slash, such as 3/8 or 7/20.
Percentage
37.5%
Decimal
0.375
Simplified fraction
3/8
Example: 3/8 = 0.375 = 37.5%. Fractions are simplified automatically, with repeating decimals approximated to a practical denominator.
Worked examples
Start with a real calculation
Select an example to load it above.
How it works
One workspace for percentages in every direction.
Choose the relationship you need instead of rearranging formulas yourself. Every mode labels its inputs, shows its working, and includes practical examples.
- 01
Choose the relationship
Select from seven tasks, including percent of, what percent, change, adjustment, reverse percentage, difference, and percentage points.
- 02
Enter values or load an example
Use positive, negative, whole, or decimal numbers, or start with a worked real-world example.
- 03
Verify or convert the answer
Review the substituted formula, choose the desired precision, or convert between fraction, decimal, and percentage forms.
Clear, verifiable answers
Useful for quick checks and serious calculations.
Three-way converter
Convert a fraction, decimal, or percentage into both other forms and get a simplified fraction automatically.
Formula transparency
Every answer includes the exact formula with your values substituted, so the result is easy to verify.
Percentage questions
Understand what each result means.
How do I calculate a percentage of a number?+
Divide the percentage by 100 and multiply it by the number. For example, 20% of 250 is 20 ÷ 100 × 250 = 50.
How is percentage change calculated?+
Subtract the starting value from the new value, divide by the absolute starting value, then multiply by 100. A positive answer is an increase and a negative answer is a decrease.
What is the difference between percentage change and percentage difference?+
Percentage change uses the starting value as its base and has a direction. Percentage difference compares two values symmetrically using their average, so neither value is treated as the original.
How do I find the original value before a percentage increase?+
Divide the final value by one plus the percentage expressed as a decimal. For example, if 120 is the value after a 20% increase, the original value is 120 ÷ 1.20 = 100.
What is the difference between percent and percentage points?+
Percentage points measure the direct gap between two percentages. Moving from 12% to 15% is an increase of 3 percentage points, but a relative percentage increase of 25%.
How do I convert a fraction or decimal to a percentage?+
Divide the fraction to get a decimal, then multiply by 100. For example, 3/8 equals 0.375, which equals 37.5%. To convert a percentage to a decimal, divide by 100.
Can percentages be greater than 100 or negative?+
Yes. A value can be more than 100% of another value, and percentage change can be negative when the new value is lower than the starting value.
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