Percentage Calculator | Percent Change and Difference
Calculate percentages, percent increase or decrease, percentage change, part-of-whole values, and original or final amounts.
1. Find Percentage of a Number
2. Find Rate (X is what % of Y?)
3. Percentage Change (Increase / Decrease)
4. Increase / Decrease a Number by Percentage
5. Find Original Number from Percentage
What the Percentage Calculator Solves
The percentage calculator handles percent of a number, percent change, increase or decrease, part-of-whole values, and comparisons between old and new numbers.
Common Percentage Questions
Use it for discounts, price increases, tax checks, growth rates, score changes, business margins, report figures, and quick classroom or spreadsheet verification.
Check the Question Type
Percentage questions often sound similar but use different formulas. Confirm whether you need percent of, percent change, increase/decrease, or original value before trusting the result.
About This Tool
Percentage Calculator solves the three common percentage problems: what is X percent of Y, X is what percent of Y, and X is Y percent of what number. It handles all directions of percentage calculation without manual formula recall.
When to Use It
Use this when calculating a tip as a percentage of a bill, when working out what percentage a value represents of a total, or when finding the original number before a percentage was applied.
How to Use
- Select the type of percentage calculation you need.
- Enter the known values.
- Click Calculate to see the result.
- Switch modes to solve a different direction of the same problem.
Frequently Asked Questions
What is the formula for percentage change?
Percentage change is the new value minus the old value, divided by the old value, multiplied by 100. A positive result is an increase, negative is a decrease.
How do I calculate what percentage 45 is of 180?
Divide 45 by 180 and multiply by 100. The result is 25 percent. Enter both numbers in the calculator for instant results.
What is the difference between percentage and percentage points?
A change from 10 to 15 percent is an increase of 5 percentage points. But it is a 50 percent increase in the rate itself. The distinction matters in financial and statistical contexts.