How to Find Percentage of a Number: Simple Guide

Whether you’re trying to calculate a discount, determine tax amounts, or analyze data, knowing how to find the percentage of a number is a useful skill in various aspects of life. Understanding this fundamental concept will empower you to make informed decisions, manage budgets, and navigate financial situations with confidence. In just a few simple steps, you’ll discover the secrets to unlocking the mysteries of percentages, enabling you to effortlessly calculate and interpret them. So, let’s delve into the world of percentages and unveil the methods to find that elusive percentage of any number!

Understanding the Concept of Percentages

Percentages are a fundamental concept in mathematics that represents a portion of a whole expressed as a fraction of 100. Being able to calculate percentages is a useful skill in various real-life situations, such as determining discounts, analyzing data, or tracking changes over time.

Understanding percentages involves recognizing that 1% is equivalent to one part out of a hundred. Thus, 50% represents half of a whole, while 75% indicates three-quarters. Familiarizing yourself with these basic conversions will make percentage calculations easier.

To find percentages, you need to know two values: the whole number and the part or portion that the percentage corresponds to. By following some simple steps, you can easily calculate percentages and use them for a variety of purposes.

Converting a Percentage to a Decimal

Converting a percentage to a decimal form is often necessary for many calculations. To do this, divide the percentage value by 100. For example, to convert 25% to a decimal, divide 25 by 100, resulting in 0.25.


  • 50% = 50 ÷ 100 = 0.5
  • 75% = 75 ÷ 100 = 0.75
  • 12.5% = 12.5 ÷ 100 = 0.125

Converting percentages to decimals is essential when working with formulas or equations that require decimal values. It simplifies calculations and enables you to perform mathematical operations more effectively.

Calculating the Percentage of a Whole Number

Calculating the percentage of a whole number involves finding a certain portion or fraction of the total value. To do this, multiply the whole number by the decimal equivalent of the percentage.


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Percentage = (Whole Number) x (Percentage in Decimal Form)


What is 20% of 80?

Percentage = 80 x 0.20 = 16

So, 20% of 80 is 16.

Knowing this calculation method allows you to find specific values from a larger set of data or determine proportions within a given context.

Finding the Percentage Increase or Decrease

Percentage increases or decreases are often encountered when tracking changes, such as price variations or population growth. To calculate a percentage increase or decrease, you need to know the original value and the new value.


Percentage Change = ((New Value – Original Value) ÷ Original Value) x 100


What is the percentage increase if the price of a product increased from $50 to $60?

Percentage Change = (($60 – $50) ÷ $50) x 100 = 20%

So, the price increased by 20%.

This calculation method is useful in numerous situations where comparing before and after values is necessary, such as financial analysis, business performance evaluation, or statistical analysis.

Determining the Original Number from a Percentage

Occasionally, you may know the percentage and the result but need to find the original number. To determine the original number, divide the result by the decimal equivalent of the percentage.


Original Number = (Result) ÷ (Percentage in Decimal Form)


If 80 is 40% of the unknown number, what is the original number?

Original Number = 80 ÷ 0.40 = 200

So, the original number is 200.

Using this calculation method, you can reverse the process of finding percentages and uncover the initial value given the result and the percentage.

Applying Percentages in Real-life Scenarios

Percentages play a significant role in many real-life scenarios. From personal finance to business calculations, they provide a deeper understanding of numerical relationships and help make informed decisions.

One practical application is budgeting. Allocating a percentage of your income towards different expenses allows you to maintain a balanced financial life. For example, you might dedicate 30% of your income to housing, 20% to savings, and 50% to living expenses.

Percentages are also used in statistics to present data in a meaningful way. Figures expressed as percentages make comparisons more accessible, allowing for better analysis and visualization of trends or patterns.

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Using Percentages for Discounts and Sales

One of the most common applications of percentages is in calculating discounts and determining sale prices. When items are marked down during a sale, the resulting price is often expressed as a percentage of the original value.

For instance, if a $100 shirt is discounted by 20%, you can calculate the sale price by finding 80% of the original value:

Sale Price = $100 x 0.80 = $80

This represents a 20% reduction from the initial price. Understanding the calculation enables you to evaluate the value of discounts quickly.

Tips and Tricks for Quick Percentage Calculations

  • Use estimation: For mental calculations, rounding numbers can make percentages easier to work with. Round the values to the nearest 10 or 5 to simplify calculations while still maintaining reasonable accuracy.
  • Divide by 2: To find 50% of a value, simply divide it by 2. This quick trick helps halve numbers efficiently.
  • Percentages of 10 and 5: Multiplying a number by 10% is the same as moving the decimal place one spot to the left. Similarly, multiplying by 5% is equivalent to moving the decimal place one spot to the left and dividing by two.
  • Use proportion: When determining percentages without using the decimal form, comparing values proportionally can simplify calculations. For example, to find 20% of a number, you can first find 10% and double it.

By employing these tips and tricks, you can quickly estimate percentages, perform mental calculations, and explore different scenarios.


Understanding how to find the percentage of a number is a valuable skill that can be applied in various practical situations. By grasping the concept of percentages, converting between decimal and percentage forms, and learning the basic calculation methods, you can effortlessly calculate percentages, determine proportions, and analyze data. Whether it’s calculating discounts, tracking changes, or solving real-life problems, percentages are an essential tool for making informed decisions and simplifying complex calculations.