Percentage Calculator
Quickly solve percentage increases, decreases, and parts.
Result
How to Use This Calculator
1 Choose Your Calculation Type
Select one of the three tabs at the top of the calculator based on what you need to solve:
- • % of Number: Best for finding a part of a whole (e.g., "What is 20% of 150?"). Great for calculating tips or simple discounts.
- • % Change: Use this to see how much a value has grown or shrunk over time (e.g., "Price went from $50 to $75").
- • What % is...: Use this to find the percentage relationship between two numbers (e.g., "25 is what percent of 100?").
2 Enter Your Values
Type your numbers into the input fields. You can use whole numbers (like 50) or decimals (like 12.5). The calculator will helpfully prevent you from dividing by zero.
3 View Results & Explanation
Click the Calculate button to process your data. The tool will display:
- The precise calculated result in large text.
- A visual badge indicating "Increase" or "Decrease" (specific to % Change mode).
- A clear sentence explaining the result in plain English.
Real-Life Examples
Calculate a Tip
"What is 20% of a $50 bill?"
Result: $10.00
Price Drop
"Price changed from $100 to $80"
Result: 20% Decrease
Test Score
"You got 45 marks out of 50"
Result: 90%
Mathematical Formulas
(Percentage ÷ 100) × Number
((New - Old) ÷ Old) × 100
(X ÷ Y) × 100
Discounts
Calculate sales price off
Growth
Track value increase
Proportions
Find the whole amount
Common Percentage Conversions
| Percentage | Decimal | Fraction |
|---|---|---|
| 1% | 0.01 | 1/100 |
| 5% | 0.05 | 1/20 |
| 10% | 0.1 | 1/10 |
| 20% | 0.2 | 1/5 |
| 25% | 0.25 | 1/4 |
| 33.3% | 0.333... | 1/3 |
| 50% | 0.5 | 1/2 |
| 75% | 0.75 | 3/4 |
| 100% | 1.0 | 1/1 |
Frequently asked questions (FAQ)
How does this online calculator compute a specific percentage of a figure?
To find a percentage of a number using this simple method, convert the percentage into a decimal by dividing by 100. Then, multiply that decimal by the figure you are analyzing. For example, to determine 20% of 50, the result is 10.
How do I ensure an accurate calculation of the percentage change between two values?
To find the difference, subtract the original number from the new one. Then, divide by the original amount and multiply by 100. This formula provides a precise output for both a percentage increase and a percentage decrease.
Change = ((New Value - Original Value) / Original Value) × 100
What is the formula for finding "what percentage X is of Y"?
Simply divide the first number (like a test score) by the total possible amount and multiply by 100. For instance, to calculate what percentage 5 is of 20: (5 ÷ 20) × 100 = 25%.
What is the first step to make a fast and easy calculation manually?
Before you input data or apply the math, the most efficient first step is to convert the raw percentage input into a decimal. For example, converting 50% to 0.50 makes it easier to estimate or compute the solution.
How do I estimate a final price after a discount or tax?
You can determine the discount amount by finding the percentage of the sticker price and subtracting it from the total. This feature is also useful to compute added costs like sales tax to find the final paying price.
How can I track value growth, such as profit or interest?
You can track financial growth using the change calculation. A positive result indicates an increase in value (like earning interest or profit), while a negative number displays a decrease.
Is there a reliable way to find the whole amount if I only know the percentage part?
Yes, using the "Proportions" function. If you know a specific figure represents a certain portion, divide that amount by the percentage (as a decimal) to find the total whole.
What specific inputs does this free tool need to function?
To be useful, the calculator generally needs you to input two of three variables: the percentage, the original number, or the new number. It will then display the missing variable.
Does this interactive tool cover both rising and falling numbers?
Yes. The interactive interface allows you to compare values to solve for both a percentage increase (growth) and a percentage decrease (loss) quickly.
What are the most efficient uses for this quick calculator?
It is designed to fast-track math tasks: compare numbers, find the % of a value, compute changes, determine discounts, and solve proportions to find the whole amount.