Percent, percentage, and percentile—trying to say that three times fast! Rooted in math and statistics, these words all sound quite alike, but they refer to different things. Even if you were someone who always dragged their feet with their math homework growing up, these are some terms that you want to be familiar with and know how to use properly since they’ll come up more often than you think in everyday situations.

Let’s take a look at how to define percent vs. percentage vs. percentile, what some examples of each are, and how to calculate them using online calculators and charts.

## What Is “Percent”?

Percent is defined as part(s) per hundred, or a specific amount for every hundred. Break the word up into “per” and “cent” and you can see the Latin origin: **“per centum,” which means “by the hundred.”**

Instead of writing out the word “percent,” you can substitute the symbol %. So, 50 percent can also be written as 50%. You would only see the percent symbol used when there’s a number in front of it (50% not fifty %).

Another way to think of percent is to look at it as a fraction or ratio where the second value is 100. For instance, 82 percent, 82 per 100, 82 out of 100, 82/100, and 82% are all the same thing!

## The Meaning of “Percentage”

It’s easy to get confused between percent and percentage, and you may find that many people interchange them without thinking twice. There is a slight difference in the definition, though. Percentage is the number or amount in each hundred. We know, we know—it seems very similar and really, it all comes down to grammar! You wouldn’t ever use a numeral in front of the word “percentage.” For example, you can say, “What is the **percentage** of people who passed the test?” Then, the answer could be “90 **percent**.”

Another more general definition of percentage is a part in relation to a whole. That’s why you’ll also hear “percentage” used to describe relationships without any specific numbers involved. For example, someone might say that a small percentage of people at the event bought a ticket in advance.

## How to Calculate Percentage

Being able to calculate percentage comes in handy in a variety of everyday situations. Maybe you want to calculate 18% of your dinner bill so you know how much tip to leave. Maybe there’s a shirt you like that’s 40% off and you want to see if the sale price is in your budget.

One of the easiest ways to do so is to simply use a percentage calculator. With a calculator like this, you can figure out what is X percent of a number (like what is 27% of 85), how much X percent of a number is (like how much 30% is of 75), and more. Just put in your two numeral values and your answer is there.

There are also calculators specifically designed to determine percentage increase and percentage decrease. With these, you type in the original value and how much percent you want the number to increase or decrease by to get the resulting value.

### Mental Math Percentage

When you don’t have your phone or computer handy to use a percentage calculator, it’s convenient to be able to do a little bit of mental math. Luckily, there are some tricks to this! First off, you should know how to find 10% and 50% of a number. Finding 10% just involves moving the decimal point one place to the left. That means 10% of 36 is 3.6. Finding 50% is as easy as dividing a number in half. That means 50% of 84 is 42.

With knowing how to get to 10% and 50% of a number, you can do a whole lot of quick mental math to come up with other percentages. For example, figuring out 5% of a number is simpler if you first determine what 10% is and then divide that by two. Another example: Finding 25% of a number is much easier if you first think of what’s 50% and then halve that. Use this logic, and you may be surprised how much faster you can calculate percentages in your head!

## “Percentile” Explained

Percentile is another word that gets thrown around with percent and percentage. They do all sound similar, but this one, in particular, is used as a statistics measure. According to Merriam-Webster, percentile is defined as “a value on a scale of 100 that indicates the percent of a distribution that is equal to or below it.”

In layman’s terms, it’s the percentage of values below a specific value. To put it another way, percentile compares a value to the rest of the values under it in a certain group.

### Percentiles in Test Taking

One situation where percentile often comes up is with test taking, like the SAT. Percentile scores will show how someone did compared to the rest of the people who took that test. For example, if your child received a composite score on the SAT between 1190 and 1280 that means they’re in the 80 to 89th percentile. In other words, 80 to 89% of the other test takers scored the same or lower than your child. That’s pretty great!

Remember, that there’s a big difference between a percent score and a percentile score when it comes to tests. You can receive a 75% on a test, which means you got 75% of the points possible, but if everyone else did worse than you, you would actually be in the 99th percentile. That’s where grading curves come in, and then your C doesn’t look so bad in comparison now!

### Percentiles for IQ

Whether or not test taking is something you’re good at may have little impact on your IQ. Percentiles can also be used to calculate your intelligence quotient, which is a measure of a person’s ability to reason. Most people have an IQ score between 85 and 115, with 130 being considered a high IQ for a very small percentage of the population attributed to 2% of test takers. You can utilize our IQ percentile calculator to understand how your IQ compares to the rest of the population.

### Percentiles for Baby Growth

In the U.S., percentiles are commonly used to track the growth of a baby. The CDC and WHO provide specific charts for different measurements including length and weight for age for infants as well as weight and BMI for age for children and adolescents. Your child’s pediatrician may use these numbers as a guideline to confirm that everything is developing on track, or whether perhaps their nutrition needs adjusting.

You may not be a baby anymore, but perhaps you’re still curious about how your height compares to the rest of the population. To figure that out, you can use a height percentile calculator. Put in your height, gender, age, and country, and you’ll see what percentage of people you’re taller than and shorter than.

## Using Percent Vs. Percentage Vs. Percentile

Whether or not you enjoyed math as a subject in school, there are countless ways that percentages and percentiles come up in the real world. Knowing how to calculate percentages and how to understand percentiles, as well as the differences between all the terms mentioned above, can help you in a variety of ways. From finalizing restaurant checks to assessing your likelihood of getting into a certain college, being able to do these equations—even with the support of a calculator—is important skill to have.

Cindy is a freelance writer and editor with previous experience in marketing as well as book publishing. Along with her content writing for a diverse portfolio of clients, Cindy’s work has been featured in Thrillist, The Points Guy, Forbes, and more.