Percentage Calculator
Calculate percentages four ways — percent of a number, what percent one number is of another, and percentage change.
%
Result
50
25% of 200 = 50
How to Use the Percentage Calculator
This free percentage calculator handles the three most common percentage tasks. Select a mode using the tabs above the calculator, enter your numbers, and the result appears instantly as you type — no button to press.
- % of a number — find what a given percentage of any number is (e.g., 25% of 200).
- What % is X of Y — find what percentage one value is of another (e.g., 30 is what percent of 150).
- % Change — find the percentage increase or decrease between two values (e.g., from 50 to 75).
Percentage Formulas
All percentage calculations come from a few core formulas:
Percentage of a number → Result = (P ÷ 100) × N
Part as a percentage → Percentage = (Part ÷ Whole) × 100
Percentage change → Change % = ((New − Old) ÷ |Old|) × 100
Part as a percentage → Percentage = (Part ÷ Whole) × 100
Percentage change → Change % = ((New − Old) ÷ |Old|) × 100
Worked Examples
Example 1: Find 25% of 200
Convert 25% to a decimal (25 ÷ 100 = 0.25), then multiply by 200: 0.25 × 200 = 50.
Example 2: 30 is what percent of 150?
Divide the part by the whole and multiply by 100: (30 ÷ 150) × 100 = 20%.
Example 3: Percentage increase from 50 to 75
Find the difference (75 − 50 = 25), divide by the original (25 ÷ 50 = 0.5), multiply by 100 = 50% increase.
Common Percentage Reference Table
| Percentage | Decimal | Fraction | Of 100 | Of 200 |
|---|---|---|---|---|
| 5% | 0.05 | 1/20 | 5 | 10 |
| 10% | 0.10 | 1/10 | 10 | 20 |
| 20% | 0.20 | 1/5 | 20 | 40 |
| 25% | 0.25 | 1/4 | 25 | 50 |
| 33.33% | 0.3333 | 1/3 | 33.33 | 66.67 |
| 50% | 0.50 | 1/2 | 50 | 100 |
| 75% | 0.75 | 3/4 | 75 | 150 |
| 100% | 1.00 | 1/1 | 100 | 200 |
Frequently Asked Questions
How do I calculate a percentage of a number?
To find a percentage of a number, convert the percentage to a decimal by dividing by 100, then multiply by the number. For example, 25% of 200 = (25 ÷ 100) × 200 = 0.25 × 200 = 50.
How do I calculate percentage increase?
Subtract the original value from the new value, divide the result by the original value, then multiply by 100. For example, an increase from 50 to 75 = ((75 − 50) ÷ 50) × 100 = 50%.
How do I calculate what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, to find what percent 30 is of 150: (30 ÷ 150) × 100 = 20%.
What is the formula for percentage change?
Percentage change = ((New Value − Old Value) ÷ |Old Value|) × 100. A positive result means an increase; a negative result means a decrease.
How do I calculate percentage decrease?
Subtract the new value from the original value, divide by the original value, then multiply by 100. For example, a decrease from 80 to 60 = ((80 − 60) ÷ 80) × 100 = 25%.
Is this percentage calculator free?
Yes. This calculator is completely free, requires no sign-up, and runs entirely in your browser. Your numbers are never stored or sent anywhere.
Can I use this calculator on my phone?
Yes. The calculator is fully responsive and works on any device — phones, tablets, laptops, and desktops — with no app to install.