Percentage Calculator

Three percentage calculations in one tool

• Percent of a number — e.g. what is 15% of 200?
• X is what percent of Y — e.g. 30 is what percent of 150?
• Percentage change — increase or decrease from one value to another

Everyday uses

Percentages appear everywhere — discounts, tips, taxes, test scores, interest rates and statistics. This calculator removes the mental math so you can get an accurate answer in seconds, whether you are shopping, studying or budgeting.

Key features at a glance

• Find a percentage of a number (e.g. 15% of 200)
• Work out what percent one number is of another
• Calculate percentage increase or decrease between two values
• Instant results as you type
• Clear, readable answers with no rounding surprises
• Runs entirely in your browser, even offline

The three percentage formulas explained

The word percent means 'per hundred', so a percentage is simply a fraction with 100 as the denominator. The first calculation — finding a percentage of a number — multiplies the number by the percentage divided by 100; 15% of 200 is 200 × 0.15 = 30. This is the form you use for tips, discounts, taxes, and commissions.

The second calculation reverses the question: to find what percent X is of Y, you divide X by Y and multiply by 100, so 30 out of 150 is (30 ÷ 150) × 100 = 20%. The third, percentage change, measures the difference between two values relative to the starting one: subtract the old value from the new, divide by the old, and multiply by 100. A rise from 80 to 100 is a 25% increase. Each formula answers a different real-world question.

Percentage points versus percent change

A subtle but important distinction trips many people up: the difference between a percentage point and a percent change. If an interest rate rises from 4% to 6%, it has increased by two percentage points, but the percent change is 50%, because 2 is half of the original 4. Confusing the two can make a modest change sound dramatic or vice versa.

This matters whenever you read statistics in the news, compare interest rates, or report results. Saying a figure 'went up 50%' and saying it 'went up two percentage points' can describe the exact same change, yet they sound completely different. Using the right calculation — absolute difference for percentage points, relative change for percent — keeps your conclusions accurate and your communication clear.

Tips for working with percentages

• To find a percent of a number, multiply by the percent divided by 100
• Remember that X% of Y always equals Y% of X — sometimes one is easier
• For percentage change, always divide by the original (older) value
• Distinguish percentage points from percent change when comparing rates
• To reverse a discount, divide by (1 − discount), not multiply

Why choose our percentage calculator?

Our calculator is completely free with no signup, no limits, and no subscription. It runs entirely in your browser, so results appear instantly, it works offline, and your numbers never leave your device.

It is one of more than 200 free tools on ToopTools, and you can pin it to your My Workspace, a personalized workspace where you keep the tools you use most in a single dashboard. Beside the discount, tax, and tip calculators, it covers every everyday percentage question in one convenient place.

Common use cases

Percentages appear everywhere in daily life: working out a discount in a sale, calculating a tip at a restaurant, adding sales tax, figuring a test score, or understanding an interest rate. This calculator removes the mental arithmetic so you get an accurate answer in seconds.

Students use it for math homework and to check their own working, shoppers use it to compare deals, and professionals use it for quick business calculations like margins, commissions, and growth rates. Having all three percentage operations in one tool means you never have to remember which formula to rearrange.

Is the percentage calculator free?

Yes. It is completely free with no account, no sign-up, and no usage limits. Calculate as many percentages as you like at no cost.

How do I calculate a percentage of a number?

Multiply the number by the percentage divided by 100. For example, 15% of 200 is 200 × 0.15 = 30. The calculator does this for you instantly when you enter the percentage and the number.

How do I find what percent one number is of another?

Divide the first number by the second and multiply by 100. For example, 30 is (30 ÷ 150) × 100 = 20% of 150. The second mode of the calculator handles this directly.

How is percentage increase or decrease calculated?

Subtract the original value from the new value, divide by the original value, and multiply by 100. A positive result is an increase and a negative result is a decrease.

What is the difference between percentage points and percent?

A percentage point is the absolute difference between two percentages, while percent change is relative to the starting value. A rise from 4% to 6% is two percentage points but a 50% increase.

How do I add or remove a percentage from a price?

To add a percentage, multiply by (1 + percent ÷ 100); to remove one that was already applied, divide by (1 + percent ÷ 100). For discounts, multiply by (1 − percent ÷ 100) to add and divide by it to reverse.

Why does reversing a percentage not use the same percent?

Because the percentage is taken from a different base. A 20% increase on 100 gives 120, but going from 120 back to 100 is only a 16.7% decrease, since the second percentage is calculated from the larger number.

Are my calculations private?

Yes. Everything is computed in your browser and nothing is uploaded, so your numbers stay private and the tool works without an internet connection.

How do I calculate a percentage change between two numbers?

Enter the original value and the new value, and the calculator finds the percentage increase or decrease between them — for example, from 80 to 100 is a 25% increase. It handles both rises and falls automatically and shows the result instantly.

Does the percentage calculator work offline?

Yes. The calculations run entirely in your browser, so once the page has loaded the tool works without an internet connection, and nothing you enter is uploaded. You can work out percentages privately on your own device.