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Percentage Calculator
Every percent calculation in one place — X% of Y, what %, % change, reverse, and more.
%
25% of 200 is
50.00
Seven Percent Problems, One Tool
Most percentage calculators make you pick one formula at a time. This one solves every common type side-by-side — so you don't have to remember which button is which.
Types Supported
- X% of Y (e.g. 18% of 2,500)
- X is what % of Y
- Percent increase / decrease
- Value after X% change
- Reverse percentage (find original before markup / discount)
- Difference in percent (between two values)
Frequently Asked Questions
How do I find X percent of Y?
Multiply Y by (X/100). 20% of 250 = 250 × 0.20 = 50. Our calculator does it instantly — just enter the two numbers.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. 40 out of 200 = 40/200 × 100 = 20%.
How is percent change calculated?
((new − old) ÷ old) × 100. Going from 80 to 100 is a 25% increase; 100 to 80 is a 20% decrease — note the base changes.
What is a reverse percentage?
Finding the original number when you know the percent and result. If 25% of X is 40, then X = 40 / 0.25 = 160.