Percentage Calculator
Calculate percentages every way.
Calculate percentages every common way: what is X% of Y, what percent X is of Y, the percentage change between two numbers, and the original value before a percentage change. Results update instantly. Everything runs locally in your browser.
What is X% of Y?
=
X is what percent of Y?
=
Percentage change
=
Original value before a change
=
Your input is processed locally in your browser — nothing is uploaded, stored or logged.
Saved you time?Buy me a coffee
How it works
- 1 Pick the calculation you need.
- 2 Enter your numbers.
- 3 Read the result instantly and copy it.
Common use cases
- Work out discounts and tips.
- Find a percentage change.
- Calculate tax or markup.
- Reverse a percentage to the original.
Frequently asked questions
Is my input sent to a server?
No. Every calculation runs locally in your browser — your input is never uploaded, stored or logged.
How is percentage change calculated?
(new − old) ÷ old × 100. A positive result is an increase, a negative one a decrease.
How do I find the original value?
If a value already includes a change of p%, the original is value ÷ (1 + p/100).
Is it really free?
Yes — free, with no signup and no limits.