How to use Percentage Calculator — Free % Calculator for Any Calculation
- 1Pick the type of percentage calculation you need.
- 2Enter the two numbers.
- 3See the result update instantly as you type.
About Percentage Calculator
Percentage questions come in a few different shapes — a discount, a grade, a year-over-year change, a tip — and it's easy to use the wrong formula for the one you actually need. This calculator separates the four most common cases into their own tabs so you always pick the right one.
Switch modes to reuse the same tool for a discount calculation, a grade percentage, a growth-rate comparison, or a straightforward increase or decrease, and see the result update as you type.
All calculation happens instantly in your browser.
Frequently asked questions
Which percentage calculations does it cover?
Four modes: 'X% of Y', 'X is what % of Y', percentage change from one number to another, and increasing or decreasing a number by a percentage.
How is percentage change calculated?
As (new value − old value) ÷ |old value| × 100, shown as a positive number for an increase and negative for a decrease.
Can I use negative numbers?
Yes, the calculator accepts negative numbers in every mode.
Does it update as I type?
Yes, the result updates live with no button to click.
Is it free?
Yes, unlimited and free, with no sign-up.