Calculator
Percentage Calculator
Three percentage calculators in one — find a percentage of a number, calculate percentage change, or find what percent one number is of another.
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📋 How To Use This Percentage Calculator
1
Choose your calculation type. Select one of the three tabs at the top depending on what you need: finding a percentage of a number, calculating a percentage change, or finding what percent X is of Y.
2
Enter your numbers. Fill in the input fields shown for your selected mode. All fields accept decimal numbers too — for example, 12.5% is perfectly valid.
3
Click Calculate. Your answer appears instantly with a clear explanation of the result so you understand exactly what the number means.
4
Switch modes freely. You can switch between the three modes at any time without losing your other inputs. Each mode is independent.
⚙️ How Each Mode Works
% of a Number
Finds X% of Y. For example, 20% of 150 = 30. Useful for calculating discounts, tips, tax amounts, or any portion of a whole.
% Change
Calculates the percentage increase or decrease between two values. Formula: ((New − Old) ÷ Old) × 100. Positive = increase, negative = decrease.
X is What % of Y
Finds what percentage X represents out of Y. For example, 45 is what percent of 180? Answer: 25%. Useful for test scores, ratios, and proportions.
Real World Use
Use this calculator for tax calculations, exam scores, profit margins, sales discounts, inflation rates, statistical analysis, and everyday math.
❓ Frequently Asked Questions
To find X% of Y, multiply Y by X and divide by 100. For example, 15% of 200 = (200 × 15) ÷ 100 = 30. Our calculator does this instantly — just enter the percentage and the number in the first tab.
Percentage increase = ((New Value − Old Value) ÷ Old Value) × 100. For example, if a price went from $80 to $100, the increase is ((100 − 80) ÷ 80) × 100 = 25%. Use the “% Change” tab in this calculator.
A percentage is a ratio expressed as a fraction of 100 (e.g. 75% means 75 out of 100). A percentile is a value below which a certain percentage of data falls in a distribution (e.g. being in the 90th percentile means you scored higher than 90% of people). They are different concepts.
Yes. All three modes in this calculator accept decimal values. For example, you can enter 12.5% or 3.75 as inputs. The calculator handles decimal precision correctly and rounds the result to two decimal places.
To reverse a percentage (find the original value before a percentage was applied), divide the final value by (1 + percentage/100) for increases, or (1 − percentage/100) for decreases. For example, if a price of $120 includes a 20% increase, the original was 120 ÷ 1.20 = $100.
Yes, completely free. No sign-up, no login, and no usage limits. All calculations happen instantly in your browser.
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