Quickly calculate percentages, percentage increase, and percentage decrease.
Find out exactly what a specific percentage of a number is.
Result = (Percentage ÷ 100) × Base Number
20 percent of 500 is 100.
Determine what percent one number is of another number.
Result = (Part ÷ Whole) × 100
50 is 25 percent of 200.
Calculate the percentage change between two values over time.
Change % = ((New - Old) ÷ Old) × 100
25 percent increase.
Numbers govern almost every aspect of our lives, from the grocery store checkout line to high-level corporate boardrooms. Among these numbers, percentages are perhaps the most ubiquitous and powerful concept. A percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%", although the abbreviations "pct.", "pct" and sometimes "pc" are also used. A percentage is a dimensionless number (pure number); it has no unit of measurement.
The concept of the percentage is rooted in the Latin phrase per centum, which translates to "by the hundred." This mathematical concept allows us to standardize comparisons. For instance, comparing a test score of 45/50 to a score of 82/100 is difficult mentally. However, converting them to percentages (90% vs 82%) makes the comparison instant and intuitive. This tool is designed to bridge that gap, providing instant clarity on any proportional calculation you might need to perform.
While mental math is a useful skill, financial and statistical accuracy is paramount. A miscalculation of a single percentage point in a mortgage interest rate, a tax return, or a chemical mixture can have significant real-world consequences. Our Percentage Calculator utilizes precise floating-point arithmetic to ensure that whether you are calculating a 15% tip on a dinner check or a 0.05% change in stock yields, the result is mathematically rigorous.
Used for finding specific portions, such as tax amounts, commissions, or ingredient ratios.
Used for tracking growth or recession over time, critical for sales analysis and weight loss tracking.
Demystifying the logic behind the calculation. Understand the math to master your finances.
To find P percent of Y, we first convert the percentage into a decimal by dividing by 100. For example, 25% becomes 0.25. We then multiply this decimal by the base number Y.
To find out what percentage X is of Y, you are essentially calculating the ratio of the part to the whole. Divide the part (X) by the whole (Y), and then multiply the result by 100 to shift the decimal place.
This formula calculates relative change. First, find the difference between the values. Then, divide that difference by the original (Old) value. Finally, multiply by 100.
Percentages are not just abstract mathematical concepts; they are the language of business, science, and daily life. Understanding how to apply these calculations can lead to smarter financial decisions and better data interpretation.
The most common use of percentages is calculating discounts. If a store offers "30% off" on an item costing $50.00, you need to calculate 30% of 50 (which is 15) and subtract it from the original price to get $35.00. Additionally, sales tax is always a percentage calculation added on top of the subtotal.
In the stock market, absolute values matter less than percentage changes. A $5 increase on a $10 stock is a massive 50% gain, whereas a $5 increase on a $1000 stock is a negligible 0.5% gain. Our "Percentage Change" tool is specifically built to help investors understand these relative movements (ROI).
Grading systems heavily rely on percentages. Calculating your grade point average (GPA) or determining what score you need on a final exam to maintain an 'A' average requires reverse percentage calculations. Furthermore, in chemistry and physics, concentration ratios and error margins are strictly percentage-based.
Scenario
Sales Tax (VAT)
Example
8% of $150 = $12.00
Scenario
Restaurant Tip
Example
18% of $60 = $10.80
Scenario
Yearly Raise
Example
50k to 55k = 10% Increase
Scenario
Weight Loss
Example
200lb to 180lb = 10% Decrease
Common queries about percentages and calculation methods.
To find a percentage, simply divide the part by the whole number. Take that decimal result and multiply it by 100 to determine the final percentage value relative to the whole.
Calculate twenty percent easily by multiplying your specific number by 0.2 directly. For instance, if you multiply 50 by 0.2, you get 10, which represents exactly twenty percent of that original value.
Subtract the original value from the new one to find the difference. Divide this difference by the original value, then multiply by 100 to reveal the precise percentage increase between the two numbers.
Ten percent is simply one-tenth of any number, found by moving the decimal one spot left. Use this easy baseline to estimate other percentages like five percent or twenty percent quickly.