Percentage Calculator — Find %, Change, Increase, Decrease
Our free percentage calculator handles the three most common percentage operations in one tool. Find a percentage of a number, work out what percentage one number is of another, or calculate the change between two values. Each mode prints the formula it used, step by step, so you can check the reasoning instead of trusting a bare figure. Percentage calculations appear everywhere — from shopping discounts and restaurant tips to grade calculations and business analytics.
Percentage change and percentage points are not the same thing, and conflating them is how misleading statistics get written. If a rate moves from 4% to 6%, that is a rise of two percentage points and a 50% increase — both true, and one sounds much more dramatic. Percentage change is also asymmetric: a 50% fall needs a 100% rise to get back to where it started, which is why a portfolio that drops by half has more work to do than the headline number suggests.
How to use Percentage Calculator
- Select the calculation type: X% of Y, X is what % of Y, % change, % difference, increase/decrease by %, or reverse (find the original).
- Enter your numbers in the input fields.
- See the result instantly with the step-by-step formula shown.
- Copy the result to clipboard with one click.
Features
- Six calculation modes — X% of Y, X is what % of Y, % change, % difference, increase or decrease by a percentage, and reverse percentage.
- Step-by-step formula — See exactly how each result is calculated.
- Real-time calculation — Results update as you type.
- Handles decimals and negatives — Works with any valid number.
- Copy result — One-click copy to clipboard.
- 100% browser-based — No server needed.
Frequently Asked Questions
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 × 20) / 100 = 30. Our calculator does this instantly — enter the percentage and number to see the result with the formula shown.
How do I calculate percentage increase between two numbers?
Use the formula: ((New Value - Old Value) / Old Value) × 100. Enter both values in our percentage change calculator to see the result automatically, including whether it's an increase or decrease.
What is the difference between percentage change and percentage difference?
Percentage change measures the shift from an old value to a new value with a clear direction (increase or decrease). Percentage difference compares any two values using their average as the base, without implying direction. Our calculator supports both.
What is the difference between a percent and a percentage point?
A percentage point is an absolute difference between two percentages; a percent change is relative. Moving from 4% to 6% is a rise of two percentage points, and also a 50% increase. Both are correct, which is exactly why the more flattering one tends to appear in headlines.
Why does a 50% loss need a 100% gain to recover?
Because each percentage is taken from a different base. Losing 50% of 100 leaves 50, and getting back to 100 from 50 means doubling — a 100% gain. Percentage changes do not cancel out, which is the arithmetic behind why large drawdowns are so costly.