Percentage Calculator
Calculate percentages, percentage change, and more
What is Percentage Calculator?
Percentage Calculator is a free online tool that performs various percentage calculations. It can calculate what percentage one number is of another, find a percentage of a number, calculate percentage increase or decrease, and solve other common percentage problems. This tool is useful for financial calculations, academic grading, shopping discounts, statistical analysis, and everyday math. Simply enter your values and get instant results. All calculations happen in your browser with no data sent to any server.
How to Use
- Select the calculation mode you need.
- Enter the values and the result is shown instantly.
Tips & Best Practices
- Use 'X is what % of Y' to calculate grades, scores, and completion rates.
- Use the percentage change mode to calculate year-over-year growth or decline.
- For shopping, calculate the final price by entering the original price and discount percentage.
- Remember that percentage increase and decrease are not symmetrical: a 50% increase followed by a 50% decrease does not return to the original.
- Use this for tip calculations by finding a percentage of your bill total.
Use Cases
Finance
Calculate interest rates, investment returns, profit margins, and tax percentages.
Shopping
Calculate discounted prices, sale savings, and compare prices across different discount rates.
Academic
Convert scores to percentages and calculate grade point averages.
Business
Calculate percentage growth, market share, and performance metrics.
FAQ
What modes does the percentage calculator have?
It offers 3 modes: (1) What is X% of Y?, (2) X is what % of Y?, (3) % change from X to Y.
How is percentage change calculated?
Percentage change = ((new value - old value) / old value) x 100.
What is the mathematical meaning of percent (%)?
Percent comes from Latin meaning 'per hundred' and is a ratio unit expressing a value relative to 100. For example, 25% = 25/100 = 0.25.
Is my data sent to any server?
No, all percentage calculations are performed locally in your browser and no data is transmitted externally.
What is the difference between percentage points (%p) and percent (%)?
Percentage points measure the absolute difference between two rates (e.g., 30% to 35% = 5%p increase), while percent measures the relative change (about 16.7% increase).
Are decimal results displayed accurately?
Yes, results are calculated and displayed with decimal precision, making the tool suitable for detailed ratio calculations.
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 20% of 150 = 150 x 20 / 100 = 30.
Is my data collected?
No, all calculations happen in your browser. No data is sent to any server.
How do I calculate percentage change?
Percentage change = ((New - Old) / Old) x 100. A positive result is an increase, negative is a decrease.
What is the difference between percentage and percentage points?
Percentage points measure the arithmetic difference. Going from 10% to 15% is a 5 percentage point increase but a 50% increase.
Can I calculate reverse percentages?
Yes, you can find the original number when you know the result and percentage applied.
How do I calculate a discount?
Final price = Original price x (1 - discount% / 100). For 20% off $50: $50 x 0.8 = $40.
What is compound percentage?
Compound percentage applies the percentage to the growing total (like compound interest), not the original value.
Can I calculate tip percentages?
Yes, enter your bill amount and desired tip percentage to calculate the tip amount.