Percentage Calculator
Category: Number & Notation ToolsCalculate percentages, percentage changes, and more
What is X% of Y?
Percentage Change
Calculate the percentage change between two values
Percentage Increase/Decrease
Calculate a value after percentage increase or decrease
Discount Calculator
Calculate sale price after discount
Understanding Percentages
A percentage is a way of expressing a number as a fraction of 100. The word "percent" means "per hundred" - it comes from the Latin "per centum".
Key Concepts
- Basic percentage: Finding what X% of Y is. For example, 15% of 200 = 30.
- Percentage change: The relative change between an old value and a new value, expressed as a percentage.
- Percentage points: Unlike percentage change, percentage points refer to the arithmetic difference between two percentages.
- Percentage increase/decrease: Finding a new value after applying a percentage change to the original value.
Common Applications
- Sales tax and discounts
- Interest rates
- Statistics and data analysis
- Business metrics like profit margins
- Academic grading systems
- Population growth or decline
Percentage Formulas
Basic Percentage
X% of Y = (X / 100) × Y
Example: 25% of 80 = (25 / 100) × 80 = 0.25 × 80 = 20
Percentage Change
Percentage Change = ((New Value - Original Value) / |Original Value|) × 100%
Example: From 50 to 75 = ((75 - 50) / 50) × 100% = (25 / 50) × 100% = 50% increase
Finding the Original Value (Reverse Percentage)
If X is Y% of the original value: Original Value = X / (Y / 100)
Example: If 30 is 25% of the original value: Original Value = 30 / 0.25 = 120
Percentage Increase
New Value = Original Value × (1 + (Percentage / 100))
Example: 50 increased by 20% = 50 × (1 + 0.2) = 50 × 1.2 = 60
Percentage Decrease
New Value = Original Value × (1 - (Percentage / 100))
Example: 80 decreased by 15% = 80 × (1 - 0.15) = 80 × 0.85 = 68
Practical Examples
Sales and Discounts
Problem: A jacket originally priced at $80 is on sale for 25% off. What is the sale price?
Solution: Sale Price = $80 × (1 - 0.25) = $80 × 0.75 = $60
Tip Calculation
Problem: Your restaurant bill is $45 and you want to leave a 18% tip. How much should you leave?
Solution: Tip Amount = $45 × 0.18 = $8.10
Business Growth
Problem: A company's revenue was $2.4 million last year and $3 million this year. What was the percentage increase?
Solution: Percentage Increase = (($3M - $2.4M) / $2.4M) × 100% = ($0.6M / $2.4M) × 100% = 25%
Tax Calculations
Problem: If the sales tax rate is 8%, what is the total price of an item that costs $120?
Solution: Total Price = $120 + ($120 × 0.08) = $120 + $9.60 = $129.60
Grade Calculation
Problem: A student scored 42 out of 50 on a test. What is the percentage score?
Solution: Percentage Score = (42 / 50) × 100% = 84%
Crunching the Numbers: Why a Percentage Calculator Makes Life Easier
The Power of Simple Math
The Percentage Calculator helps you solve percentage problems fast and without stress. You can use it to find out what a certain percent of a number is, figure out how much prices have dropped, see how much something increased, or even calculate a discount on your favorite item. No need to search for formulas or grab a pencil—it’s all in one place.
Math problems with percentages show up in everyday life. Maybe you’re figuring out how much you saved during a sale or checking your grade in class. This tool takes out the guesswork and does the math for you in seconds.
Even if numbers aren't your best friend, this calculator makes things simple. It's like having a math helper by your side.
All the Handy Buttons and Tabs
This Percentage Calculator has different tabs that each do something cool:
- Basic – Find out what X% of any number is.
- % Change – See how much something has increased or decreased, like comparing test scores or prices.
- Increase/Decrease – Add or subtract a percent to see a new value (great for price markups or markdowns).
- Discount – Find out how much you’re saving and what the new price is during a sale.
Each section has clearly labeled inputs and shows you the formula used, so you can understand the math behind the scenes.
Real-Life Math Magic
Here’s where this calculator becomes super useful in your everyday world:
- School Assignments: Let’s say your test score was 42 out of 50. The calculator can show that’s 84%. Boom—grade sorted.
- Shopping: You see a shirt on sale for 25% off. The calculator helps you find the new price and how much you save.
- Money Management: If your rent increased from $800 to $880, you can quickly check it’s a 10% jump.
- Tipping at Restaurants: Want to leave a 20% tip on a $45 bill? Just plug it in and get the answer instantly.
No need to scratch your head or search online for how to do it. The calculator does it right away.
Quick and Easy Steps to Use It
Using the Percentage Calculator is simple. Here's a step-by-step for the most popular tab: Basic.
- Choose the Basic tab.
- Type the percent in the first box (like 20%).
- Enter the value in the second box (like 200).
- Hit Calculate.
- See the result and the formula used.
For the other tabs, just switch between them and follow the same idea—fill in the blanks, press calculate, and you’re done.
Each section tells you exactly what to put in, so you won’t feel lost.
Equal Signs and Easy Wins
Math doesn’t have to be confusing or scary. With this Percentage Calculator, you can figure things out fast, whether it’s for class, shopping, or just satisfying your curiosity. It’s like your pocket-sized math buddy—always ready to help and never asking for a snack in return.
From calculating a test score to finding out how much pizza you ate at a party (yep, that's math too), this tool keeps things clear and simple.
Just remember: even when numbers look tricky, there's a shortcut—and it might just be one click away.