Percentage Calculator
Percentage of a number, ratios & change
What is % of ?
is what percent of ?
is % of what?
From to
Convert % to a decimal & fraction
How to Use
- 1Pick a mode: % of a number, find the percentage, or change.
- 2Type your two numbers into the highlighted boxes.
- 3The answer updates instantly on the purple display.
- 4Press Reset to clear and start a new calculation.
Percentage Formulas
- Percentage of a number P% of X = (P ÷ 100) × X
- Find the percentage X of Y = (X ÷ Y) × 100%
- Find the total X is P% of X ÷ (P ÷ 100)
- Percentage change X → Y = ((Y − X) ÷ X) × 100%
- Percent to decimal / fraction P% = P ÷ 100
Quick Examples
Tap an example to load it above.
Everything about the Percentage Calculator
A quick, practical guide to working with percentages the easy way.
A percentage is simply a way of expressing a number as a fraction of 100, since the word literally means "per hundred". This percentage calculator handles the three questions people ask most: what is P% of a number, what percent one number is of another, and the percentage increase or decrease between two values. It runs free in your browser, on any device, with nothing to install.
Percentages are everywhere in daily life: discounts and sales tax while shopping, tips at a restaurant, exam scores, interest on savings and loans, and statistics in the news. Getting them right by hand is easy to slip up on, so this tool does the arithmetic for you and shows the result the moment you type.
Tip: To find a percentage of a number quickly, move the decimal point two places left, then multiply, so 15% of 200 becomes 0.15 × 200 = 30.
How to use this calculator
- 1 Choose the right mode
Use the three tabs to switch between "% of a number", "find the percentage" and "increase / decrease".
- 2 Enter your two numbers
Fill the highlighted boxes in the sentence and the calculator reads it just as you would say it out loud.
- 3 Read the instant result
The answer appears on the purple display and updates live, with an increase/decrease label for percentage change.
- 4 Try an example or reset
Tap any example chip to load real numbers, or press Reset to clear the fields and start again.
The three percentage formulas
Frequently Asked 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 (15 ÷ 100) × 200 = 30. In the "% of a number" tab, just type 15 and 200 and the answer appears instantly.
How do I find what percent one number is of another?
Divide the first number by the second, then multiply by 100. For example, 30 out of 200 is (30 ÷ 200) × 100 = 15%. Use the "Find the percentage" tab and enter the part and the whole.
How is percentage increase or decrease calculated?
Subtract the original value from the new value, divide by the original value, then multiply by 100. Going from 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25% increase. A negative result means a decrease.
What is the difference between percentage change and percentage points?
They are not the same. If a rate rises from 20% to 25%, that is a 5 percentage-point rise, but a 25% percentage change (5 ÷ 20 × 100). Percentage points compare the percentages directly; percentage change compares them relative to the starting value.
How do I add or subtract a percentage from a price?
To add P%, multiply by (1 + P/100); to subtract, multiply by (1 − P/100). A $50 item with 20% tax costs 50 × 1.20 = $60, and the same item at 20% off costs 50 × 0.80 = $40.
Is this percentage calculator free and does it work on mobile?
Yes. It's 100% free, needs no sign-up and no download. It works in any modern browser and is fully responsive, so it fits phones, tablets and desktops. Your numbers stay in your browser; nothing is stored or shared.