Percentage Calculators - Help & Documentation

Learn how to use our percentage calculator tools efficiently with this comprehensive guide

Requirements and Important Information

  • JavaScript Support

    The Handy Percent application requires that JavaScript support is enabled in your web browser. Ensure JavaScript is active to use all functionalities smoothly.

  • Decimal Separators

    You may use the decimal separator suitable for your locale. For example:

    • In the United States and United Kingdom, use a dot (.), e.g., 10.5.
    • In many European countries, use a comma (,), e.g., 10,5.
  • Thousands Separator

    The thousands separator is ignored by the application when you type. You don't need to include it in your input. For instance, pasting 1,000 or 1.000 from the clipboard (depending on your locale settings) is treated simply as 1000.

  • Instant Calculations

    All calculations are performed instantly, in real-time, as you type your values. There's no need to press any button to see the results.

Helpful Calculator Features

Our calculators include several features to make your calculations faster and easier:

Easy Clipboard Integration

  • Quickly paste numbers from your clipboard with the automatic Paste button (Chrome only)
  • Instantly copy your results by clicking Add to History (copies to clipboard and saves to history)
  • Results are copied as plain numbers without additional text

Keyboard Shortcuts

  • Press Enter to move to the next field, copy the result to the clipboard, and save to history
  • Press Escape to clear all fields and start fresh
  • Use Space to move between input fields quickly

Calculation History

  • Calculations are automatically saved to your history
  • Click on any previous calculation to reload those values
  • Easily delete single items or clear the entire history
  • History is stored locally in your browser for future use
  • Each calculator stores up to 20 most recent calculations, automatically removing the oldest entries when this limit is reached

Customize Your Calculator

  • Drag and drop calculators to prioritize your most frequently used tools
  • Press and hold the mouse button on the calculator's icon, drag the calculator to your preferred position, then release the button
  • Your customized order is saved automatically

Mobile-Friendly Design

  • Our calculators are fully responsive and work seamlessly on any device
  • A mobile-friendly menu allows easy navigation between pages (Calculators, Help, and Privacy Policy)
  • Designed with touch-friendly buttons and inputs suitable for all screen sizes

Additional Features

  • Quickly toggle between light and dark modes
  • Visual mathematical formulas provided for clarity
  • Input validation ensures accurate and reliable results

Basic Percentage CALCULATOR

Calculate the percentage value of a given number quickly and easily.

How to Use

  • Enter the desired percentage (X) into the first input field.
  • Enter your main number (Y) into the second input field.
  • Optionally, check the "Round" box to round the result to two decimal places.
  • The calculated result is shown instantly as you type.
  • Click "Add to History" or press Enter to save your calculation.

How It Works

The Basic Percentage calculator uses this formula:

Result=Percentage100×Number\text{Result} = \frac{\text{Percentage}}{100} \times \text{Number}

For example, to find 15% of 200, the calculator computes:

15100×200=0.15×200=30\frac{15}{100} \times 200 = 0.15 \times 200 = 30

So the result is 30.

Practical Uses

  • Finding sale discounts (e.g., 20% off an $80 product).
  • Calculating taxes (e.g., 8% tax on a $250 item).
  • Checking grades (e.g., 85% of total points).
  • Measuring nutritional intake (e.g., 40% daily value).
  • Determining tips at restaurants (e.g., 15% tip on a $60 bill).
  • Calculating interest (e.g., 5% annual interest on a $1000 investment).
Go to Basic Percentage CALCULATOR

Original Value CALCULATOR

The Original Value calculator (also known as reverse percentage calculator) helps you find the original value when you know a percentage and its result. This is useful for working backward from a known percentage to find the original amount.

How to Use

  1. Enter the percentage (X) in the first input field.
  2. Enter the result value (Z) in the second input field.
  3. Optionally, check the "Round" box to round the result to two decimal places.
  4. The calculator will instantly show the original value (Answer).
  5. Click "Add to History" or press Enter to save your calculation.

How It Works

The Original Value calculator uses this formula:

Original Value=ResultPercentage/100\text{Original Value} = \frac{\text{Result}}{\text{Percentage} / 100}

For example, if 25% of some value is 50, the original value would be:

5025/100=500.25=200\frac{50}{25 / 100} = \frac{50}{0.25} = 200

So the original value is 200.

When to Use

  • Finding the original price before a discount was applied
  • Calculating the total amount before tax when you know the tax percentage and tax amount
  • Determining the original value when you know what percentage of it equals a specific amount
  • Figuring out the original salary when you know the percentage raise and new salary
  • Finding the original investment amount when you know the percentage return and final value
Go to Original Value CALCULATOR

Part-to-Whole Percentage CALCULATOR

Find what percentage one number is of another quickly and accurately.

How to Use

  • Enter the total value (Y) in the first input field (after "of").
  • Enter the partial value (Z) in the second input field (after "is").
  • The calculator will instantly show what percentage of Y is Z.
  • Optionally, check the "Round" box to round the result to two decimal places.
  • Click "Add to History" or press Enter to save your calculation.

How It Works

The Part-to-Whole Percentage calculator uses this formula:

Percentage=ZY×100%\text{Percentage} = \frac{\text{Z}}{\text{Y}} \times 100\%

For example, to find what percentage 25 is of 100, the calculator computes:

25100×100%=25%\frac{25}{100} \times 100\% = 25\%

So 25 is 25% of 100.

Practical Uses

  • Calculating test scores (e.g., how many points you got out of the total).
  • Determining market share (e.g., a company's sales compared to total industry sales).
  • Analyzing budget allocations (e.g., how much of your budget goes to a specific expense).
  • Measuring progress toward goals (e.g., current savings compared to savings target).
  • Calculating completion percentage (e.g., tasks completed out of total tasks).
  • Determining batting averages in sports (e.g., hits divided by at-bats).
Go to Part-to-Whole Percentage CALCULATOR

Percentage Change CALCULATOR

Calculate the percentage difference between two values to determine increases or decreases.

How to Use

  • Enter the original (old) value in the first input field.
  • Enter the new value in the second input field.
  • Optionally, check the "Round" box to round the result to two decimal places.
  • The calculator will instantly show the percentage change.
  • A positive result indicates an increase; negative indicates a decrease.
  • Click "Add to History" or press Enter to save your calculation.

How It Works

The Percentage Change calculator uses this formula:

Percentage Change=New Value−Old ValueOld Value×100%\text{Percentage Change} = \frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100\%

For example, if a value increases from 50 to 75, the calculator computes:

75−5050×100%=2550×100%=0.5×100%=50%\frac{75 - 50}{50} \times 100\% = \frac{25}{50} \times 100\% = 0.5 \times 100\% = 50\%

This shows a 50% increase from the original value.

Practical Uses

  • Monitoring stock price changes over time.
  • Evaluating salary increases or decreases.
  • Tracking weight loss or gain percentages.
  • Analyzing business revenue growth year-over-year.
  • Assessing performance improvements in sports or academics.
  • Calculating inflation rates by comparing prices over time.
  • Measuring changes in website traffic or conversion rates.
Go to Percentage Change CALCULATOR

Tip CALCULATOR

Calculate tip amounts and total bills easily for any dining or service experience.

How to Use

  • Enter the bill amount in the first input field.
  • Select or input your preferred tip percentage.
  • Optionally, check the "Round" box to round the result to two decimal places.
  • To split the bill, enter the number of people in the "Split" field.
  • The calculator will instantly show your calculated tip and total amount.
  • If splitting, it will also show the amount each person should pay.
  • Click "Add to History" or press Enter to save your calculation.

How It Works

The Tip calculator uses these formulas:

Tip Amount:

Tip Amount=Bill Amount×Tip Percentage100\text{Tip Amount} = \text{Bill Amount} \times \frac{\text{Tip Percentage}}{100}

Total Amount:

Total Amount=Bill Amount+Tip Amount\text{Total Amount} = \text{Bill Amount} + \text{Tip Amount}

Example: For a $50 bill and 20% tip:

Tip Amount:

$50×20100=$50×0.2=$10\$50 \times \frac{20}{100} = \$50 \times 0.2 = \$10

Total Amount:

$50+$10=$60\$50 + \$10 = \$60

Practical Uses

  • Calculating tips at restaurants or for food deliveries.
  • Adjusting tips for different service levels (15% standard, 20% good, 25% excellent).
  • Calculating tips while traveling internationally (adapting to local currency and tipping customs).
  • Splitting the bill among several people after a group meal or gathering.
  • Determining appropriate tips for hotel staff, tour guides, or other service providers.
  • Budgeting for meals including the tip amount.
Go to Tip CALCULATOR

Tips for Accurate Calculations

  • Double-check input numbers for accuracy.
  • Use decimal points for precision.
  • Calculations update instantly as you type.
  • When the Round checkbox is checked, numbers are rounded to 2 decimal places.

© 2025 Bilargo. All rights reserved.