Percentage Calculators - Help & Documentation
Master our percentage tools quickly with this easy-to-follow guide.
Quick Start & Requirements
- JavaScript Required
Handy Percent runs entirely in your browser. Just make sure JavaScript is enabled to get started.
- Decimal Separators
Use the decimal separator that matches your locale settings. For example:
- In the US and UK, use a dot (.), e.g., 10.5.
- In many European countries, use a comma (,), e.g., 10,5.
- Thousands Separator
Thousands separators are ignored when you type. You don't need to include them. For instance, pasting 1,000 or 1.000 (depending on your locale) is handled correctly as simply 1000.
- Instant Results
Calculations happen in real-time as you type. No need to hunt for a "Calculate" button.
Helpful Calculator Features
Our calculators include several features to make your calculations faster and easier:
Smart Clipboard
- Paste numbers instantly with the Paste button (Chrome only).
- Click Add to Memos to copy results and save them simultaneously.
- We copy plain numbers, so they're ready to use anywhere.
Keyboard Shortcuts
- Enter saves to memos or moves to the next field.
- Escape clears everything for a fresh start.
- Space jumps between fields.
Drag-to-Adjust Values
- Click and hold any number field, then drag left or right to adjust the value.
- Power user tip! Hold Alt (or Option) for larger jumps, or Shift for whole numbers.
Calculation Memos
- Your calculations are saved automatically.
- Click any previous entry to reload it instantly.
- Clear single items or wipe the slate clean with one click.
- Your data stays private—everything is stored right in your browser.
- We keep your last 20 calculations, automatically making room for new ones.
Customize Your Layout
- Drag and drop calculator cards to rearrange them.
- Put your favorites at the top for quick access.
- Your layout is saved automatically.
Mobile-Friendly
- Works perfectly on phones, tablets, and desktops.
- Touch-friendly buttons and clear navigation.
Extras
- One-click Dark Mode.
- Visual formulas to help you understand the math.
- Smart validation ensuring precise results every time.
Basic Percentage CALCULATOR
Calculate the percentage value of a given number.
Practical Uses
- Daily Nutritional Value:
40% [X] of a standard US 2,000 [Y] calorie diet is how many calories [Z]?
800 calories - Grade Points:
Scoring 85% [X] on a 120 [Y] point University final earns how many points [Z]?
102 points - Investment Interest:
5% [X] APR on a $1,000 [Y] high-yield savings account earns how much [Z]?
$50 - Restaurant Tip:
A 15% [X] tip on a $60 [Y] Olive Garden bill comes to how much [Z]?
$9 - Sale Discount:
20% [X] off a $80 [Y] pair of Levi's jeans saves you how much [Z]?
$16 - Tax Calculation:
8% [X] NYC sales tax on a $250 [Y] AirPods Pro comes to how much [Z]?
$20
How to Use
- Enter a percentage in the first box.
- Type the total number you're calculating from in the second box.
- The answer appears instantly.
- Need 2 decimal places? Just check the "Round" box.
- Press Enter or click "Add to Memos" to save your work.
How It Works
The Basic Percentage calculator uses this formula:
Example: What is 20% of 80?
So 20% of 80 is 16.
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.
Practical Uses
- Pre-Discount Price:
25% [X] of what original price [Y] is a $50 [Z] discount on a smartwatch?
$200 - Pre-Tax Amount:
8% [X] of what pre-tax amount [Y] is $16 [Z] sales tax?
$200 - Original Value:
15% [X] of what dinner bill [Y] is a 30 [Z] tip?
200 - Pre-Raise Salary:
10% [X] of what original base salary [Y] is a $5,000 [Z] raise?
$50,000 - Investment Principal:
12% [X] of what original seed capital [Y] is a $2,400 [Z] return?
$20,000 - Total Budget:
30% [X] of what total Christmas budget [Y] is $600 [Z]?
$2,000
How to Use
- Type the percentage in the first box.
- Enter the resulting number in the second box.
- The calculator instantly reveals the original value (the starting number before the percentage was applied).
- Check "Round" if you want to keep the decimals tidy.
- Hit "Add to Memos" or Enter to save it for later.
How It Works
The Original Value calculator uses this formula:
Example: If 15% equals 30, the original value is:
So the original value is 200.
Part-to-Whole Percentage CALCULATOR
Find what percentage one number is of another.
Practical Uses
- Batting Average:
batting average [X%] for a Yankees player with 100 [Y] at-bats and 30 [Z] hits?
30% - Rent Share:
What percentage [X%] of your $4,000 [Y] monthly income goes to $800 [Z] rent in Houston?
20% - Market Share:
What is Tesla's market share [X%] if total EV sales are $1,000,000 [Y] and Tesla sells $250,000 [Z]?
25% - Savings Progress:
What percentage [X%] of your $10,000 [Y] emergency fund have you reached with $7,500 [Z] saved?
75% - Task Completion:
What percentage [X%] of 24 [Y] weekly chores is 18 [Z] completed tasks?
75% - Test Score:
What is your grade [X%] on a 100 [Y] point Bar Exam section when scoring 85 [Z] points?
85%
How to Use
- Enter the total number (Y) in the first box.
- Enter the part (Z) in the second box.
- See instantly what percentage the part is of the total.
- Check "Round" if you prefer a standard 2-decimal answer.
- Press Enter or "Add to Memos" to keep it for later.
How It Works
The Part-to-Whole Percentage calculator uses this formula:
For example, to find what percentage 25 is of 100, the calculator computes:
So 25 is 25% of 100.
Percentage Change CALCULATOR
Calculate the percentage difference between two values to determine increases or decreases.
Practical Uses
- Inflation Rate:
A concert ticket rising from $100 [Original] to $103 [New] represents what inflation rate [Change%]?
3% - Performance Improvement:
Monthly sales leads improving from 70 [Original] to 84 [New] represents what percentage improvement [Change%]?
20% - Revenue Growth:
Small business revenue growing from $1,000,000 [Original] to $1,200,000 [New] represents what percentage growth [Change%]?
20% - Salary Change:
A Target manager's salary increase from $50,000 [Original] to $54,000 [New] represents what percentage raise [Change%]?
8% - Stock Price Change:
Netflix stock going from $50 [Original] to $75 [New] represents what percentage change [Change%]?
50% increase - Website Traffic Change:
A drop in Etsy shop visits from 10,000 [Original] to 8,500 [New] represents what percentage change [Change%]?
15% decrease - Weight Loss:
Weight dropping from 180 [Original] lbs to 162 [New] lbs on a Keto diet represents what percentage change [Change%]?
10% decrease
How to Use
- Enter the old value in the first box.
- Enter the new value in the second box.
- The calculator instantly shows the percentage difference.
- We'll tell you if it's an increase (positive) or decrease (negative).
- Press Enter or "Add to Memos" to save the result.
How It Works
The Percentage Change calculator uses this formula:
For example, if a value increases from 50 to 75, the calculator computes:
This shows a 50% increase from the original value.
Increased Value CALCULATOR
Calculate the new value after increasing an original amount by a specific percentage.
Practical Uses
- Budget Boost:
A $5,000 [Original] Disney World trip budget increased by 25% [Increase] becomes what [New]?
$6,250 - Investment Growth:
A $2,000 [Original] Roth IRA growing by 12% [Increase] becomes what [New]?
$2,240 - Population Growth:
A city like Austin of 100,000 [Original] people with 3% [Increase] growth reaches what population [New]?
103,000 - Price Inflation:
A $120 [Original] grocery bill with 5% [Increase] inflation becomes what [New]?
$126 - Rent Increase:
Monthly rent of $1,200 [Original] in Denver with a 7% [Increase] hike becomes what [New]?
$1,284 - Salary Increase:
A $50,000 [Original] nurse salary increased by 8% [Increase] becomes what [New]?
$54,000
How to Use
- Enter your starting number in the first box.
- Type the percentage growth in the second box.
- The calculator instantly displays the new, higher total.
- Check "Round" for a standard 2-decimal result.
- Hit Enter or "Add to Memos" to save it.
How It Works
The Increased Value calculator uses this formula:
For example, to find the new value when $1,000 is increased by 15%, the calculator computes:
So the new value is $1,150.
Original Before Increase CALCULATOR
Calculate the original value before a percentage increase, given the new value and percentage increase.
Practical Uses
- Budget (Pre-Raise):
What was the original wedding budget [Original] before a 25% [Increase] raise made it $6,250 [New]?
$5,000 - Investment (Pre-Growth):
What was the original Bitcoin investment [Original] before a 12% [Increase] growth made it worth $2,240 [New]?
$2,000 - Price Before Hike:
What was the original cable bill [Original] before a 5% [Increase] hike made it $126 [New]?
$120 - Rent Before Raise:
What was the original rent [Original] in Chicago before a 7% [Increase] raise made it $1,284 [New]?
$1,200 - Pre-Growth Population:
What was the original population of Boise [Original] before a 3% [Increase] growth brought it to 103,000 [New] people?
100,000 - Salary Before Raise:
What was the original start-up salary [Original] before an 8% [Increase] raise made it $54,000 [New]?
$50,000
How to Use
- Type the percentage gain in the first box.
- Enter the final (higher) number in the second box.
- We'll instantly calculate what the value was before the increase.
- Use the "Round" checkbox for a cleaner 2-decimal result.
- Save it to Memos with Enter or the "Add to Memos" button.
How It Works
The Original Before Increase calculator uses this formula:
For example, to find the original value when the new value is $1,150 after a 15% increase, the calculator computes:
So the original value was $1,000.
Important Note
When the increase percentage is -100%, the calculation is undefined because you cannot divide by zero. The calculator will show an error message in this case.
Decreased Value CALCULATOR
Calculate the new value after decreasing an original amount by a specific percentage.
Practical Uses
- Budget Cut:
A $10,000 [Original] party budget cut by 25% [Decrease] becomes what [New]?
$7,500 - Employee Reduction:
A 500 [Original]-person tech startup reduced by 10% [Decrease] leaves how many people [New]?
450 people - Energy Savings:
A $200 [Original] summer AC bill reduced by 18% [Decrease] becomes what [New]?
$164 - Sale Discount:
A $300 [Original] North Face jacket with a 30% [Decrease] discount costs what [New]?
$210 - Stock Price Drop:
A $45 [Original] Ford stock declining by 12% [Decrease] becomes what [New]?
$39.60 - Weight Loss:
Weighing 180 [Original] lbs and losing 15% [Decrease] for summer leaves what weight [New]?
153 lbs
How to Use
- Enter your starting number in the first box.
- Type the percentage decrease in the second box.
- Check "Round" if you want to keep the result to two decimal places.
- The calculator instantly shows you the new, lower value.
- Hit "Add to Memos" or Enter to save it.
How It Works
The Decreased Value calculator uses this formula:
For example, to find the new value when $800 is decreased by 20%, the calculator computes:
So the new value is $640.
Original Before Decrease CALCULATOR
Calculate the original value before a percentage decrease, given the new value and percentage decrease.
Practical Uses
- Budget (Pre-Cut):
What was the original renovation budget [Original] before a 25% [Decrease] cut made it $3,750 [New]?
$5,000 - Investment (Pre-Loss):
What was the original stock portfolio [Original] before a 12% [Decrease] loss made it worth $1,760 [New]?
$2,000 - Expense Before Cut:
What were the original subscription costs [Original] before a 7% [Decrease] cut made them $930 [New]?
$1,000 - Salary Before Cut:
What was the original freelance income [Original] before an 8% [Decrease] drop made it $46,000 [New]?
$50,000 - Pre-Decline Population:
What was the original population of Detroit [Original] before a 3% [Decrease] decline left it at 97,000 [New] people?
100,000 - Price Before Discount:
What was the original price [Original] before a 5% [Decrease] Target Circle discount made it $95 [New]?
$100
How to Use
- Type the percentage dropped in the first box.
- Enter the final (lower) number in the second box.
- We'll instantly calculate what the value was before the decrease.
- Use the "Round" checkbox for a cleaner 2-decimal result.
- Save it to Memos with Enter or the "Add to Memos" button.
How It Works
The Original Before Decrease calculator uses this formula:
For example, to find the original value when the new value is $950 after a 5% decrease, the calculator computes:
So the original value was $1,000.
Important Note
When the decrease percentage is 100%, the calculation is undefined because you cannot divide by zero. The calculator will show an error message in this case.
Tips for Accurate Calculations
- Verify Inputs: A small typo can make a big difference.
- Use Decimals: For precision, always use decimal points (e.g., 10.5).
- Instant Updates: Results appear immediately—no waiting.
- Rounding: Check "Round" to tidy up your results to 2 decimal places.