Math Calculator
Percentage Calculator
Last Updated On
Easily solve common percentage problems. Whether you need to find a percentage of a number, figure out what percentage one number is of another, or calculate the percentage change (increase or decrease) between two values, our tool provides instant, accurate results with step-by-step explanations.
Percentage Calculator
Calculate percentages, ratios, and changes
Results
Result
30
Percent of a Whole vs Percent Change
A percentage always compares a part with a reference value. For “X% of Y” the reference is the whole; for a percent change it is the starting value, which is why going up and coming back down give different percentages.
Understanding Percentages
A percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%". For example, 45% is equal to 45/100, 0.45, or 9/20.
Percentages are used widely in everyday life to express how large or small one quantity is relative to another quantity. From calculating discounts during shopping to computing interest rates and analyzing statistical data, understanding how to work with percentages is a fundamental mathematical skill.
Percentage Formulas
Our calculator uses these standard mathematical formulas to compute results:
Common Uses for Percentages
- Discounts & Sales: Calculate the final price of an item after a discount, or determine the percentage saved.
- Growth & Decline: Measure how much a value has grown or shrunk over time, such as population changes, stock prices, or business revenue.
- Proportions: Find out what portion of a total is represented by a specific part, like the percentage of a budget spent on housing.
Frequently Asked Questions
- How do I calculate a percentage?
- To calculate a percentage, divide the part by the whole and multiply by 100. For example, if you have 20 apples out of a total of 50, you divide 20 by 50 to get 0.4. Then multiply by 100 to get 40%.
- How do you calculate percentage increase or decrease?
- Subtract the old value from the new value, then divide that difference by the absolute value of the old value. Multiply the result by 100. If the result is positive, it's an increase. If it's negative, it's a decrease.
- What is X% of Y?
- To find X% of Y, convert the percentage X into a decimal by dividing by 100, then multiply by Y. For example, to find 15% of 200: (15 ÷ 100) × 200 = 0.15 × 200 = 30.