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General Calculator

Percentage Calculator

Calculate a percentage of a number, find what percentage one value represents of another, or calculate percentage increase and decrease with this free online calculator.

Calculate a Percentage

Select the type of calculation you need and enter the required values.

What Is a Percentage?

A percentage expresses a value as a part of 100. The percentage symbol is "%". For example, 25% means 25 out of 100.

How to Find a Percentage of a Number

To calculate a percentage of a number, divide the percentage by 100 and multiply it by the number.

Formula:

(Percentage ÷ 100) × Number
20% of 200 = (20 ÷ 100) × 200 = 40
15% of 300 = (15 ÷ 100) × 300 = 45

How to Find What Percentage One Number Is of Another

When you know a part and a whole, use:

Percentage = (Part ÷ Whole) × 100
40 out of 200 = (40 ÷ 200) × 100 = 20%

How to Calculate Percentage Increase

Percentage increase compares a new value with the original value.

Percentage Increase = ((New Value - Original Value) ÷ Original Value) × 100
Original value: 100
New value: 125
Increase: 25
Percentage increase: 25%

How to Calculate Percentage Decrease

Percentage decrease measures how much a value has fallen compared with its original value.

Percentage Decrease = ((Original Value - New Value) ÷ Original Value) × 100

Percentage Change Example

Suppose a value falls from 200 to 150.

Difference: 200 - 150 = 50
50 ÷ 200 = 0.25
0.25 × 100 = 25%

Common Percentage Calculator Mistakes

  • Using the wrong original or reference value.
  • Forgetting to divide a percentage by 100.
  • Confusing percentage change with percentage points.
  • Using the new value instead of the original value when calculating increase or decrease.
  • Entering the wrong numbers or decimal values.

Everyday Uses of Percentages

Percentages appear in many everyday situations, including discounts, grades, statistics, business reports and changes in prices.

A percentage calculator can help reduce manual calculation and make repeated calculations faster.

Important Note About Calculator Results

A calculator produces a mathematical result based on the values entered. Always review the inputs and make sure the selected calculation matches the question you are trying to answer.

Percentage Calculator FAQ

Common questions about percentage calculations.

Divide the percentage by 100 and multiply the result by the number.

Divide the part by the whole and multiply by 100.

Subtract the original value from the new value, divide by the original value and multiply by 100.

Subtract the new value from the original value, divide by the original value and multiply by 100.

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