Percentage Calculators & Math Tools
Explore our collection of easy-to-use percentage calculators. Whether you need to find a percentage of a number, determine what percentage one value is of another, compare two values, or calculate an increase or decrease, these tools provide fast and clear results.
Percentage Calculation Tools
What Percent of Calculator
Find what percentage one number represents of another number with a simple calculation.
Percentage Calculator
Calculate percentages, percentage values, and common percentage problems quickly and accurately.
Percentage Change
Calculate the percentage change between an original value and a new value.
Percentage Difference
Compare two values and calculate their percentage difference using the standard formula.
Percentage Increase & Decrease
Calculate percentage increases, decreases, and the final value after a percentage change.
Essential Percentage Concepts & Knowledge
Understanding the basic percentage formulas makes it easier to choose the right calculator and interpret your results correctly.
🔢 What Is a Percentage?
A percentage is a way of expressing a number as a fraction of 100. The word percentage literally means "per hundred." For example, 25% means 25 out of 100, which is equal to 0.25 as a decimal.
📐 Basic Percentage Formula
To calculate a percentage of a number, convert the percentage to a decimal and multiply it by the number. For example, 20% of 150 is 0.20 × 150 = 30.
📈 Percentage Change vs. Percentage Difference
Percentage Change: Used when comparing an original value with a new value. The original value is normally the reference point. Percentage Difference: Used to compare two values when neither value is treated as the original or baseline. The average of the two values is used as the reference.
➕ Percentage Increase & Decrease
A percentage increase means a value becomes larger relative to its original value, while a percentage decrease means it becomes smaller. The original value is important because the same numerical difference can represent very different percentages depending on the starting value.
Percentage Formulas & Quick Reference
Use these standard formulas to understand how the percentage calculations work.
Percentage value = (Percentage ÷ 100) × Number. Example: 15% of 200 = 30.
Percentage = (Part ÷ Whole) × 100. Example: 25 is 20% of 125.
Percentage change = ((New Value − Original Value) ÷ Original Value) × 100.
Percentage difference = |Value 1 − Value 2| ÷ ((Value 1 + Value 2) ÷ 2) × 100.
New value = Original value × (1 + Percentage ÷ 100).
New value = Original value × (1 − Percentage ÷ 100).
How to Calculate Percentages: Step-by-Step Guide
Percentage calculations become straightforward when you identify the type of problem first. Follow these steps:
- Identify the values: Determine the original value, new value, part, or whole involved in the problem.
- Choose the correct percentage calculation: Decide whether you need a basic percentage, percentage change, percentage difference, or increase/decrease calculation.
- Convert the percentage when necessary: Divide a percentage by 100 to convert it into a decimal. For example, 35% becomes 0.35.
- Apply the formula: Substitute your numbers into the appropriate formula and calculate the result.
- Check the reference value: For percentage change and percentage increase/decrease, make sure you are using the correct original or baseline value.
- Interpret the result: A positive percentage change generally represents an increase, while a negative percentage change represents a decrease.