Percentage Calculator

This free percentage calculator handles three of the most common percentage calculations you'll encounter in everyday life, school, or business. Each mode uses straightforward mathematical formulas to give you instant, accurate results as you type.

What is X% of Y? — Multiply Y by X and divide by 100. For example, 15% of 200 equals (200 × 15) ÷ 100 = 30. This is useful for calculating tips, sales discounts, taxes, or any scenario where you need to find a percentage of a total amount.

X is what % of Y? — Divide X by Y and multiply by 100. For example, 30 is what percent of 150? (30 ÷ 150) × 100 = 20%. Use this when you know a part and whole and want to understand the proportion — like calculating your score on a test or figuring out what portion of your budget went to groceries.

Percentage Change — Calculate how much a value has increased or decreased as a percentage. Formula: ((New - Old) ÷ Old) × 100. An increase from 80 to 100 is a 25% increase. A decrease from 100 to 80 is a 20% decrease. This mode is particularly useful for tracking price changes, analyzing data trends, or comparing performance over time.

All results update instantly as you type — no need to press Enter or wait for a button. The animated result counter and progress bar give you a visual sense of the magnitude of your calculation, making the numbers easier to interpret at a glance.