Percentage Calculator

Calculate percentages, percentage increase/decrease, and solve percentage problems with step-by-step explanations and formulas.

Calculate Percentage of a Number

Find what percentage of a number equals another number

of
Example: 20% of 150 = ?

What Percentage Is One Number of Another

Find what percentage one number represents of another

is what % of
Example: 30 is what % of 120?

Calculate Percentage Increase/Decrease

Find the percentage change between two numbers

to
Example: Change from 100 to 120 = ?% increase

Find Original Number Before Percentage Change

Calculate the original number before a percentage increase/decrease

after
Example: What number increased by 20% equals 120?

Popular Percentage Calculations

20% of 150
Common discount calculation
25 is what % of 100
Basic percentage question
100 to 120
20% increase
15% of 80
Tip calculation
200 to 150
25% decrease
120 after 20% increase
Find original: 100

About Our Percentage Calculator

The Percentage Calculator is a comprehensive and free tool designed to solve all types of percentage problems with step-by-step explanations. Whether you're a student learning percentage concepts, a professional calculating discounts and markups, or anyone needing quick percentage calculations, our calculator provides accurate results with detailed formulas and explanations.

Key Features

Our percentage calculator offers multiple calculation types to handle any percentage problem:

  • Percentage of a Number: Calculate what percentage of a number equals (e.g., 20% of 150)
  • What Percentage: Find what percentage one number is of another (e.g., 30 is what % of 120)
  • Percentage Change: Calculate percentage increase or decrease between two numbers
  • Original Number: Find the original number before a percentage change
  • Step-by-Step Breakdown: Detailed explanations showing how calculations are performed
  • Copy to Clipboard: Easy copying of results for use in other applications
  • Popular Examples: Quick access to common percentage calculations
  • Mobile-Friendly: Fully responsive design that works on all devices
  • No Registration Required: Use the tool immediately without creating an account

How to Use the Percentage Calculator

  1. Select the type of percentage calculation you need from the tabs
  2. Enter the required numbers in the input fields
  3. Click the "Calculate" button to get your result
  4. Review the step-by-step breakdown to understand the calculation
  5. Copy the result to clipboard if needed
  6. Use popular examples for quick calculations
  7. Clear all fields to start a new calculation

Percentage Calculation Types Explained

Our calculator handles four main types of percentage calculations, each with specific use cases:

1. Percentage of a Number

Formula: (Percentage ÷ 100) × Number = Result

Example: 20% of 150 = (20 ÷ 100) × 150 = 30

Use Cases:

  • Calculating discounts and sale prices
  • Finding tax amounts
  • Determining tip amounts
  • Computing commission payments
  • Calculating interest amounts

2. What Percentage Is One Number of Another

Formula: (Part ÷ Whole) × 100 = Percentage

Example: 30 is what % of 120? = (30 ÷ 120) × 100 = 25%

Use Cases:

  • Calculating test scores and grades
  • Finding completion percentages
  • Determining market share
  • Computing efficiency ratios
  • Analyzing survey results

3. Percentage Increase/Decrease

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

Example: Change from 100 to 120 = ((120 - 100) ÷ 100) × 100 = 20% increase

Use Cases:

  • Analyzing price changes
  • Measuring growth rates
  • Calculating salary increases
  • Tracking performance improvements
  • Comparing year-over-year changes

4. Original Number Before Percentage Change

Formula for Increase: Final Value ÷ (1 + Percentage/100) = Original

Formula for Decrease: Final Value ÷ (1 - Percentage/100) = Original

Example: What number increased by 20% equals 120? = 120 ÷ 1.20 = 100

Use Cases:

  • Finding original prices before markup
  • Calculating base salaries before raises
  • Determining initial investments
  • Working backwards from final amounts
  • Reverse engineering percentage problems

Real-World Applications

Percentage calculations are essential in many aspects of daily life and professional work:

Business and Finance

  • Sales and Discounts: Calculate sale prices, discount amounts, and savings
  • Taxes: Compute sales tax, income tax, and tax deductions
  • Interest Calculations: Determine loan interest, savings interest, and investment returns
  • Profit Margins: Calculate markup, profit percentages, and margin analysis
  • Commission Calculations: Determine sales commissions and referral fees
  • Budget Analysis: Allocate budget percentages and track spending

Education and Academics

  • Grade Calculations: Convert test scores to percentages and letter grades
  • GPA Calculations: Determine weighted averages and academic performance
  • Statistics: Calculate percentiles, probability, and data analysis
  • Research: Analyze survey results and experimental data
  • Progress Tracking: Monitor learning progress and completion rates

Health and Fitness

  • Body Composition: Calculate body fat percentage and muscle mass
  • Nutrition: Determine daily value percentages and macronutrient ratios
  • Fitness Goals: Track progress toward weight loss or gain targets
  • Medical Dosages: Calculate medication dosages based on body weight
  • Heart Rate Zones: Determine target heart rate percentages

Shopping and Consumer Decisions

  • Price Comparisons: Compare discounts and determine best deals
  • Tip Calculations: Calculate appropriate tips for services
  • Cashback and Rewards: Determine rewards percentages and savings
  • Loan Comparisons: Compare interest rates and loan terms
  • Insurance: Calculate deductibles and coverage percentages

Percentage Tips and Best Practices

Here are helpful tips for working with percentages effectively:

Common Percentage Conversions

  • 50% = 1/2 = 0.5 - Half of any number
  • 25% = 1/4 = 0.25 - Quarter of any number
  • 10% = 1/10 = 0.1 - Move decimal point one place left
  • 1% = 1/100 = 0.01 - Move decimal point two places left
  • 100% = 1 - The whole amount
  • 200% = 2 - Double the original amount

Mental Math Shortcuts

  • 10%: Move decimal point one place to the left
  • 5%: Calculate 10% and divide by 2
  • 15%: Calculate 10% + 5%
  • 20%: Calculate 10% and multiply by 2
  • 25%: Divide the number by 4
  • 50%: Divide the number by 2

Avoiding Common Mistakes

  • Percentage vs. Percentage Points: Understand the difference between relative and absolute changes
  • Base Number Confusion: Always identify what number represents 100%
  • Rounding Errors: Be careful with rounding in multi-step calculations
  • Negative Percentages: Understand when negative percentages indicate decreases
  • Over 100%: Remember that percentages can exceed 100% in growth scenarios

Whether you're a student mastering percentage concepts, a business professional calculating financial metrics, or someone making everyday purchasing decisions, our Percentage Calculator provides the accuracy and educational value you need. Start calculating percentages today and gain confidence in your mathematical skills!