When people need to work out a percentage of a number, they are usually trying to answer a very practical question. How much is 15% of a bill? What is 25% of a salary increase? How much tax is 7% of a purchase? These are everyday calculations that show up in shopping, budgeting, finance, and business decisions.

A percentage represents a part of a whole. The word literally means “per hundred.” So when you want to find out what X% of Y is, you are simply working out how many parts out of 100 belong to a total amount.

The basic formula looks like this:

Percentage value = (X ÷ 100) × Y

For example, if you want to calculate 20% of 150, you divide 20 by 100 to get 0.2, then multiply that by 150. The result is 30.

That method works, but doing this repeatedly can become slow and frustrating, especially when you are dealing with decimals or larger numbers. That is why using an online calculator is often the fastest option. Instead of converting percentages and double‑checking your math, you can simply enter the numbers and get an accurate result instantly.

You can try our main calculator here: https://percentagecalculator.io

This is especially helpful when you are working with:

• shopping discounts
• salary bonuses
• interest payments
• tax calculations
• commission rates

A common mistake people make is forgetting to convert the percentage into a decimal before multiplying. Another is mixing up which number represents the percentage and which represents the total value.

Using a dedicated calculator removes that confusion. It ensures that you are working with the correct formula every time and avoids small errors that can lead to incorrect financial decisions.

Whether you are calculating tips at a restaurant or planning business costs, knowing how to find a percentage of a number is one of the most useful math skills you can apply in daily life.