Percentage Calculator
Calculate percentages: what is X% of Y, and what percent is X of Y.
What is Percentages?
A percentage calculator covering the three most common queries — part-of-whole, ratio-to-percent, and percent change (increase/decrease).
How it works
Each mode applies its formula (value × percent ÷ 100, part ÷ whole × 100, and (new − old) ÷ old × 100) with results rounded to your chosen precision.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Everyday percentages
Find that 15% of 80 is 12, that 24 is 30% of 80, and that an item marked down from 50 to 40 is a 20% discount — all three operations in one tool.
Common mistakes
Percent change vs percentage of
Going from 100 to 150 is a 50% increase, but 150 is 150% of 100. The tool separates these three common interpretations.
Frequently asked questions
Which calculations are supported?
X% of Y, X is what % of Y, percent change, and percentage-point differences — each labeled clearly.
How does percent change work?
It's the difference divided by the original value: (new − old) / old × 100. The tool shows the formula with the result.