Percentage Calculator
Free percentage calculator. Find what X% of Y is, work out what percent one number is of another, and calculate the percentage increase or decrease between two values.
What is 20% of 150?
30
What is X% of Y?
X is what percent of Y?
Percent Change from X to Y
How It Works
Pick the calculation you need
Use the first card to find a percentage of a number, the second to express one number as a percent of another, or the third to measure a percentage change.
Enter your two numbers
Type your values into each mini-calculator. Results update instantly as you type — there is no submit button.
Read the result
Each card shows its own answer, and the headline result at the top mirrors "what is X% of Y" for quick reference.
A percentage is simply a number expressed as a fraction of 100. The word literally means "per hundred", so 25% is the same as 25 ÷ 100, or 0.25. Percentages let you compare quantities of different sizes on a common scale, which is why they appear everywhere from shopping discounts and tax rates to test scores and statistics.
This calculator bundles the three percentage questions people ask most often into one place: finding a percentage of a value, expressing one value as a percentage of another, and measuring how much a value has grown or shrunk. Each calculation is independent and updates live, so you can solve everyday percentage problems without reaching for a formula sheet.
Frequently Asked Questions
How do I find X percent of a number?
Divide the percentage by 100 and multiply by the number. For example, 20% of 150 is (20 ÷ 100) × 150 = 30. The first card on this page does exactly that as you type.
How do I work out what percent one number is of another?
Divide the first number by the second and multiply by 100. For example, 30 is what percent of 150? (30 ÷ 150) × 100 = 20%. The second card handles this calculation.
How is percentage change calculated?
Subtract the old value from the new value, divide by the old value, then multiply by 100: ((new − old) ÷ old) × 100. A positive result is an increase and a negative result is a decrease.
What is the difference between percentage change and percentage points?
Percentage change is relative to the starting value, while percentage points are an absolute difference between two percentages. Going from 10% to 15% is a 5 percentage-point rise but a 50% percentage increase.
Related Calculators
Build with our Percentage Calculator API
Integrate our high-speed conversion engine directly into your own applications. Get free api keys for percentage calculation api and more.