Percentage calculator

Easily calculate percentages from a value to another value, or from a percentage to a value.

Enable JavaScript to use the interactive tool. The guide below explains how it works.

Percentage Calculator

What it does

The Percentage Calculator is a versatile math utility designed to solve the most common percentage-based problems. It features three distinct modes:

Finding a percentage of a number: (e.g., "What is 15% of 200?")
Finding the percentage relationship: (e.g., "50 is what percent of 200?")
Calculating percentage change: (e.g., "What is the percentage increase from 100 to 150?")

Why someone uses it

Business & Finance: For calculating tax, tips, discounts, and profit margins.
Data Analysis: To determine growth rates, performance metrics, and statistical distributions.
Daily Life: Calculating savings, interest rates, or adjusting recipes.
Speed and Accuracy: To get instant results without having to remember formulas or use a complex scientific calculator.

Step-by-step instructions

1. Calculate a Percentage of a Value

Navigate to the first card: "What is [X] % of [Y]".
Enter the percentage in the first box and the total number in the second box.
The result appears instantly in the third box.

2. Calculate Percentage of Two Numbers

Navigate to the second card: "[X] is what percent of [Y]".
Enter the partial value in the first box and the total value in the second box.
The result (the percentage) will be shown in the final box.

3. Calculate Percentage Increase or Decrease

Navigate to the third card: "What is the percentage increase/decrease".
Enter your starting value in the "From" box.
Enter your final value in the "To" box.
The percentage change will be displayed instantly. A negative result indicates a decrease.

Examples

Shopping: You want to find 20% off a $85 item. Enter 20 and 85 in the first calculator. Result: $17.
Test Scores: You got 18 out of 24 questions right. Enter 18 and 24 in the second calculator. Result: 75%.
Investment Growth: Your stock went from $120 to $150. Enter 120 and 150 in the third calculator. Result: 25% increase.

FAQs

How do I interpret a negative result in the increase/decrease calculator? A negative result means there was a percentage decrease. For example, going from 100 to 80 will result in -20%.
Does the tool handle decimals? Yes, you can enter decimal numbers in any of the fields for precise calculations.
What happens if I divide by zero? If you enter 0 in a denominator field (like the "Y" in "X is what percent of Y"), the tool will return an empty result as division by zero is mathematically undefined.
Is the result rounded? The tool provides high-precision results suitable for most technical and financial applications.

Common mistakes

Confusing "From/To" order: In the increase/decrease calculator, swapping the "From" and "To" values will give you the wrong perspective on the change.
Percentage as Decimal: Entering 0.05 in the percentage field when you mean 5%. The tool expects the percentage as a whole number.
Swapping X and Y: In the "X is what percent of Y" calculator, make sure the "part" goes in the first box and the "whole" in the second.

Use cases

Marketing: Calculating the "Click-Through Rate" (CTR) by seeing what percent of viewers clicked an ad.
Accounting: Calculating VAT or sales tax on an invoice.
Fitness: Tracking percentage change in body weight or lift strength over time.
Cooking: Scaling recipes up or down by a specific percentage.

Related tools

Math Evaluator: For performing more complex calculations beyond simple percentages.
ETA Calculator: To calculate time and progress percentages.
Date-Time Converter: Useful when you need to calculate percentages of time periods.

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