Percent Change Calculator
Did the value go up or down? Find out exactly how much!
The starting number before the change.
The number you have now.
Enter values to start
Understanding Percent Change
Welcome to your go-to Percent Change Calculator! Have you ever seen a price tag change and wondered, “How much of a deal is that really?” Alternatively, perhaps you looked at your improved test scores and wanted to know the exact percentage of your growth. Fundamentally, that is exactly what percent change tells us. In short, it is a way to describe how much a number has gone up or down in relation to its original starting point.
Moreover, percent change is one of the most useful concepts in middle school math because it appears everywhere in the real world. For example, whether you are calculating sales tax and discounts at the mall or understanding population growth in science class, knowing the difference between an “increase” and a “decrease” is a superpower.
The Magic Formula
Percent Change = (Difference ÷ Original) × 100
First: Find the difference (New Value – Original Value).
Next: Divide that difference by the Original Value.
Finally: Multiply by 100 to get the percentage.
Why use a Percent Change Calculator?
Although the math is simple once you practice, it is easy to make small mistakes. This is especially true when deciding if the result is a positive or negative change. Therefore, a Percent Change Calculator helps you double-check your work instantly. Additionally, it visualizes the difference between the “Old” value and the “New” value, helping you clearly see if the bar went up (Increase) or down (Decrease).
Real World Examples
- Discounts: A video game drops from $60 to $45. That is a percent decrease!
- Height: You grew from 50 inches to 52 inches over the summer. That is a percent increase!
- Followers: Your social media page went from 100 followers to 150. That represents a massive 50% growth.
Frequently Asked Questions (FAQ)
Can a percent change be negative?
Yes, absolutely! Specifically, if the new number is smaller than the original number, the change is negative. Consequently, this is called a percent decrease. Our Percent Change Calculator will show this with a minus sign or a “decrease” label.
What if the original value is zero?
This is a tricky math rule! Unfortunately, you cannot divide by zero. As a result, if you start with 0 and grow to 10, the percent increase is technically undefined (or infinite), because you cannot calculate a percentage of zero.
Is 100% increase doubling?
Exactly! For instance, if you have 5 apples and you get 5 more (10 total), you increased by 100%. On the other hand, if you triple your amount, that is a 200% increase.
Keep practicing! Using a Percent Change Calculator is a great way to verify your homework and get comfortable with how numbers grow and shrink.