Percentage 電卓

計算する percentages, 見つける what percent one number is of another, or determine the whole from a percentage.

Calculate Percentages

パーセンテージの計算方法

A percentage is a way of expressing a number as a fraction of 100. Percentages are used everywhere — from calculating discounts and tips to determining grades and interest rates.

The Three Basic Percentage Problems

1. Finding a percentage of a number

Example: "What is 25% of 200?"

(25 ÷ 100) × 200 = 50

2. Finding what percentage one number is of another

Example: "50 is what percent of 200?"

(50 ÷ 200) × 100 = 25%

3. Finding the whole from a part and percentage

Example: "50 is 25% of what?"

50 ÷ (25 ÷ 100) = 200

Frequently Asked Questions

How do I calculate a percentage of a number?
To find X% of Y, divide X by 100 and multiply by Y. For example, 25% of 200 = (25 ÷ 100) × 200 = 50.
How do I calculate percentage increase or decrease?
Percentage change = ((New Value - Old Value) ÷ Old Value) × 100. A positive result indicates an increase; negative indicates a decrease.