Updated Everyday Math

Percentage Calculator

Quickly work out percentage change, what percent one number is of another, reverse percentages, and convert decimals to percentages.

Percentage Change Percent Of Reverse Percentage Decimal ⇄ Percent

All-in-One Percentage Calculator

Switch between percentage increase and decrease, percent of, reverse percentage, and decimal to percent tools.

This tab compares two values and shows the change as both an amount and a percentage.

Use this when you want to know something like “What is 20% of 250?”

Use this to answer questions like “50 is what percent of 200?”

Use this when you know the final value after a percentage increase or decrease and want to find the original value.

This tab focuses on the magnitude and direction of the percentage change between two values.

Use this tab to switch between decimal and percent formats for easier mental math and comparisons.

Percentage Calculator – Fast Percentage Math for Everyday Use

This Percentage Calculator brings together the most common percentage problems into one simple tool. You can compare two values, work out percent of a number, find what percent one number is of another, reverse a percentage, and convert between decimals and percentages.

How Percentage Change Works

When you compare an original value and a new value, the percentage change shows how big the difference is relative to the original. The basic formula is:

Percentage Change = (New − Old) ÷ Old × 100

If the result is positive, it is a percentage increase. If it is negative, it is a percentage decrease.

What Is X% of Y?

This is one of the most common percentage questions. The formula is:

X% of Y = (X ÷ 100) × Y

For example, 20% of 250 is (20 ÷ 100) × 250 = 50.

X Is What % of Y?

When you know a part and the whole, the percentage is:

Percentage = (Part ÷ Whole) × 100

For example, 50 is 25% of 200 because 50 ÷ 200 = 0.25 and 0.25 × 100 = 25%.

Reverse Percentages

Reverse percentages help you find the original value before an increase or decrease. If a final value F is the result of applying a percentage p% to an original value O:

F = O × (1 + p ÷ 100) (for an increase)
O = F ÷ (1 + p ÷ 100)

The reverse percentage tab applies this idea to quickly recover the original number.

Percent and Decimal Conversion

Percentages and decimals are two ways of writing the same thing:

Decimal = Percentage ÷ 100
Percentage = Decimal × 100

For example, 25% is 0.25 as a decimal, and 0.075 as a decimal is 7.5%.

Use this percentage calculator whenever you need quick, accurate percentage calculations for discounts, taxes, grades, statistics, and financial comparisons. You can also explore more free calculators on MyTimeCalculator for finance, fitness, health, math, and science.

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