Percentage Calculator
Free online percentage calculator. Compute X% of Y, find what percent X is of Y, calculate percentage change, and increase or decrease values by a percentage.
What is X% of Y?
AI developer workflow fit
Use Percentage Calculator while building with AI coding assistants, agents, and LLM workflows: validate generated output, transform payloads, debug integrations, and prepare reliable inputs without leaving your browser.
What Is a Percentage Calculator?
A percentage calculator is a tool that performs common percentage-related math operations. It supports four calculation modes: finding a percentage of a value, determining what percentage one number is of another, computing the percentage change between two values, and increasing or decreasing a number by a given percentage. All results are computed instantly in the browser with no rounding errors.
How to Use the Percentage Calculator
- Select a calculation mode from the tabs: X% of Y, X is what % of Y, % Change, or % Increase/Decrease.
- Enter the required numbers in the input fields.
- The result is calculated live as you type.
- Click the copy button to copy the result to your clipboard.
Common Use Cases
- Discounts & Sales Tax — Quickly calculate sale prices, discount amounts, or tax totals when shopping or preparing invoices.
- Financial Analysis — Determine percentage change in revenue, profit margins, or investment returns over time.
- Tip Calculation — Figure out how much to tip at a restaurant by calculating a percentage of the bill.
- Grade & Score Conversion — Convert raw scores to percentages or determine what fraction of total points were earned.