Percentage Calculator Online

Percentage Calculator

Formula: Result = X × Y%

Value X

Percentage Y%

Result 20

100 × 20% = 20

Formula: Percentage = (X ÷ Y) × 100%

Part Value X

Total Value Y

Percentage 20%

(20 ÷ 100) × 100% = 20%

Formula: Change % = ((New - Original) ÷ Original) × 100%

Original Value

New Value

Change +20%

((120 - 100) ÷ 100) × 100% = +20%

Formula: Discounted Price = Original × (1 - Discount Rate)

Original Price

Discount Rate %

Quick Discount:

Discounted Price $209.30

299 × (1 - 30%) = $209.30, save $89.70

Features

Multiple Calculations

Supports four common percentage calculation scenarios

Real-time Calculation

Results displayed instantly as you enter values

Detailed Process

Shows calculation formulas and detailed steps

Discount Calculator

Shopping discount calculation, savings at a glance

Increase/Decrease

Calculate percentage change in values

Simple & Easy

Clean interface, simple and intuitive operation

How to Use

Select Calculation Type

Choose the appropriate calculation type based on your needs: what is Y% of X, X is what percentage of Y, percentage increase/decrease, or discount calculation.

Enter Values

Enter the values you need to calculate in the corresponding input boxes. Results update in real-time.

View Results

View the calculation result and detailed calculation process to understand the logic. Discount calculation also supports quick discount buttons for fast setup.

Use Cases

Shopping Discounts

Mall sales, promotional activity calculations

Data Analysis

Data growth rate, proportion calculation

Financial Calculations

Interest rates, tax rates, fee calculations

Study & Exams

Score percentage, pass rate calculation

Salary Tax Calculation

Personal income tax, social security contribution ratio

Daily Spending

Discounts, cashback ratio calculation

Percentage Knowledge

What is a Percentage?

A percentage is a way of expressing a proportion, ratio, or fraction value with 100 as the denominator. Percentages are usually represented by the symbol "%", read as "percent". For example, 20% means twenty hundredths, or 0.2. Percentages are widely used in daily life for various proportional calculations, such as discounts, interest rates, growth rates, proportions, etc.

Example: 20% = 20/100 = 0.2, 20% off = 80% = 0.8

What are common percentage calculation formulas?

1. Find a percentage of a number: Result = Value × Percentage%
2. Find what percentage one number is of another: Percentage = (Part ÷ Whole) × 100%
3. Growth/Decrease rate: Change rate = ((New - Original) ÷ Original) × 100%
4. Discount calculation: Discounted price = Original × (1 - Discount rate%)

What's the difference between percentage points and percent?

Percentage is a way of expressing relative proportion, while percentage points are the unit of percentage change. For example, if the interest rate rises from 5% to 7%, we say "it increased by 2 percentage points", not "it increased by 2%". Because a 2% increase as a relative change would mean 5% growing by 2% is 5.1%. Using percentage points avoids ambiguity and clearly expresses the absolute change amount.

FAQ

Q: Is the percentage calculator free?

A: Completely free, no registration or login required, no usage limits. Just open the webpage and use it.

Q: What should I enter for 20% off?

A: 20% off means a reduction of 20%, so enter 20 in the discount rate field. That is, multiply the original price by 80% (0.8). For example, if the original price is $100 and it's 20% off: 100 × (1 - 20%) = $80.

Q: What does a negative growth rate mean?

A: A negative growth rate means the value has decreased, i.e., negative growth. For example, going from 100 to 80, the growth rate is ((80-100)÷100)×100% = -20%, indicating a decrease of 20%.

Q: What's the difference between percentage and percentage points?

A: Percentage is a relative proportion, while percentage points are the absolute unit of percentage change. For example, if an interest rate rises from 3% to 5%, it's an increase of 2 percentage points, but the relative growth is (5-3)/3×100%≈66.67%. Using percentage points to express absolute change is more accurate.

Q: How do I calculate completion rate?

A: Completion rate = Actual completed ÷ Target × 100%. For example, if the target is 100 units and 85 are completed, the completion rate is 85÷100×100%=85%. You can use our "X is what % of Y" function to calculate this.

Q: How do I calculate compound interest?

A: The compound interest formula is: Final value = Principal × (1 + interest rate)^number of periods. For example, with a principal of $10,000, an annual interest rate of 5%, and a 3-year term: Final value = 10,000 × (1+5%)^3 ≈ $11,576.25. This calculator is mainly for simple percentage calculations. For complex compound interest calculations, we recommend using a specialized financial calculator.