Percentage Calculator

Solve any percentage problem in seconds — with the steps shown

Percentages appear everywhere in daily life, from sale signs and tax rates to test scores, tips, and interest. Yet the mental arithmetic trips many people up, especially when the question is phrased differently from what they practised at school. Our free percentage calculator removes the guesswork by covering the three most common types of question in one place: finding a percentage of a number, discovering what percentage one value is of another, and measuring the percentage change between two numbers.

What sets this tool apart is that it never hides the working. For every calculation it lays out the formula, substitutes your figures, and walks through each step to the final answer. That transparency is perfect for students learning the underlying method, professionals double-checking a figure before a meeting, and anyone who simply wants to trust the result. Because the steps are written in plain language, you also learn the technique as you go and can reproduce it by hand next time.

Everything runs instantly inside your browser with no signup, no ads getting in the way of the math, and no data ever leaving your device. Type your numbers and results update immediately, so you can explore different scenarios — a bigger discount, a higher score, a steeper price rise — without clicking a calculate button each time. Whether you are budgeting, studying, shopping, or reporting, this calculator turns fiddly percentage sums into a quick, reliable answer.

Why use Percentage Calculator?

Three modes in one tool

Switch between percent-of, what-percent, and percentage-change without leaving the page or opening another calculator.

Full working shown

Every answer comes with the formula, your substituted numbers, and step-by-step reasoning so you understand how it was solved.

Instant, reactive results

Answers recalculate as you type, letting you compare scenarios and spot the impact of changing a single value.

Private and free

No account, no server calls, and no tracking of your numbers — everything happens locally in your browser.

How to use Percentage Calculator

1
Pick your calculation mode
Choose whether you want a percentage of a number, what percent one value is of another, or the change between two numbers.
2
Enter your figures
Type the values into the labelled fields. The calculator accepts decimals and negative numbers where appropriate.
3
Read the instant answer
The result appears immediately in large, clear text so it is easy to read at a glance or on a shared screen.
4
Follow the steps
Expand the working to see the formula and each calculation stage, then copy the answer if you need it elsewhere.

Common use cases

Checking a discount

Confirm the price after a percentage is knocked off, or verify a store's advertised saving before you buy.

Grading and test scores

Turn marks like 47 out of 60 into a percentage to see where a score falls and compare it to a passing threshold.

Tracking growth or decline

Measure how much a figure such as revenue, weight, or website traffic rose or fell between two periods.

Everyday budgeting

Work out tips, tax, commission, and interest quickly so you always know exactly what you are paying or earning.

Features at a glance

Three calculation modes: X% of Y, X is what % of Y, and % change
Step-by-step working displayed for every calculation
Reactive results that update as you type
Handles decimals and negative values
Copy the answer to your clipboard with one click
Clear labelling so the right numbers go in the right fields
Works on desktop, tablet, and mobile browsers
100% client-side with no data leaving your device

Frequently asked questions

How do I calculate what percentage one number is of another?

Divide the part by the whole and multiply by 100. For example, 25 out of 200 is 25 ÷ 200 × 100 = 12.5%. Use the 'X is what % of Y' mode in our calculator and it shows the full working automatically so you can follow along.

How do I find a percentage of a number?

Convert the percentage to a decimal by dividing by 100, then multiply by the number. To find 15% of 80, calculate 0.15 × 80 = 12. Our 'X% of Y' mode does this instantly and displays each step for clarity.

How is percentage change calculated?

Percentage change is the difference between two values divided by the original value, times 100. If a price rises from 50 to 65, the change is (65 − 50) ÷ 50 × 100 = 30% increase. A negative result means a decrease.

What is the difference between percentage change and percentage points?

Percentage change is relative to the starting value, while percentage points measure the absolute gap between two percentages. Moving from 10% to 15% is a 5 percentage-point rise but a 50% relative increase. This tool calculates relative percentage change.

Is this percentage calculator free and private?

Yes. The calculator is completely free with no signup, and every calculation runs directly in your browser. Nothing you type is sent to a server, logged, or stored, so it is safe for financial figures and sensitive numbers.

Your privacy matters

Percentage Calculator runs entirely in your web browser. Your files, text, and data are never uploaded to any server, never stored, and never seen by us or any third party. This client-side architecture means you can safely process confidential business documents, personal records, and proprietary data without privacy concerns.