Percentage Change Calculator: Increase and Decrease (Formula & Examples)

Percentage Change Calculator


What Is Percentage Change?

It is helpful to look at the fundamentals of the concept of percentages before demonstrating how to use a % calculator to determine percent change, percent difference, or percentage of one number from another.

A percentage is a dimensionless number that is expressed as a fraction of 100, for example, 1 out of 10 is equal to 10% and 50 out of 100 is written as 50%. By definition, a percentage is a ratio. The symbol for percent is “percent,” however the abbreviation “pct” is often used instead, and “per cent” can be found in earlier literature and documents, where “cent” is an abbreviation of the Latin “centum,” which properly means “one hundred,” therefore the phrase literally means “per one hundred.”

The use of percentages is commonplace and has a wide range of applications. They are prevalent in the social sciences, accounting, finance, and economics. We come across percent-off coupons frequently in daily life. The percentage of a previous reference price for a good or service is frequently used to represent promotions, sales, and different discounts. Calculations based on percentages can be used to gauge a person’s or machine’s productivity or workload, as in “he is working at 100 percent” (at maximum capacity).

The relative growth or fall of something, such as a population, capital, a person’s personal fortune, etc., is expressed as a percentage rise or reduction. Any two items’ differences can be stated as ratios or percentage differences. A percentage calculator can be used to quickly calculate the measurement inaccuracy of a tool or process in terms of percent error.

How can you figure out % change?

Most people mean this when they ask “how to calculate percentage,” although there are various methods that can be used; see below for more information. When comparing numbers, business metrics, or other measurements over two time periods, with the earlier period serving as the baseline, percent change calculators are frequently used.

When comparing a new state of affairs to an earlier one, such as when using the census to compare the population of villages in a particular municipality before and after industrialization, a percentage change estimate is also helpful. Although you can also determine the % change on your own, our calculator makes it incredibly easy to calculate percent increase or reduction.

For instance, let’s imagine you analyse your company’s success on a monthly basis and discover that you had 80 consumers last month, compared to only 64 the month before. Use the following calculation to compute percent change in order to determine your company’s growth rate relative to its base value from the previous month.

Formula for Percent Change

Percent change = new / old * 100 – 100

where new denotes a quantity or measure that is more recent, and old denotes a measure that is more dated. This would be 80/64 * 100 – 100 = 1.25 * 100 – 100 = 125 – 100 = 25% in the example above. You can use the percentage change calculator to confirm that your monthly percentage change (percent growth, percent rise) was 25 percent in comparison to the baseline from the previous month.

In another scenario, you might be considering a proposal to raise your income from $100,000 to $120,000 per year in order to stay on the payroll, and you want to know what percentage the new wage is compared to your old one. Start by dividing 120,000 by 100,000 to get 1.2 if you’re doing the arithmetic by hand. then divide by 100 to obtain 120. Finally, take away 100, leaving 20 percent. Since the new compensation represents 120 percent of your current salary, you were therefore given a 20 percent pay raise.


The calculator can also be used to determine how quickly certain means of transportation change. A high-speed train going at 120 miles per hour is twice as quick as a car or bus moving at 60 miles per hour, according to the percentage change, which can be calculated as 100 percent.

How can you figure out what percentage of X is Y?

Imagine you work as a car salesman and you have a car that was initially priced at $50,000. After doing some math, you find that you can reduce the price by $5,000 and still make money from the transaction. How do you calculate $5,000 as a percentage of $50,000? Obviously, entering the values directly into the % calculator above is the quickest method, but you can also perform the calculations manually by using the following formula:

Formula: X is what percentage of Y

x is x / y * 100 % of y

Therefore, in this instance, 5,000/50,000 * 100 = 0.1 * 100 = 10%. It would be a 10% discount if you gave a $5,000 off coupon on a $50,000 automobile.

In a different scenario, you might want to determine the percentage of your annual revenue that must be paid in taxes. Your tax rate is 36,000 / 80,000 / 100 = 0.45 * 100 = 45 percent since $36,000 is 45 percent of $80,000 if your yearly income is $80,000 and you’ve determined that your entire tax obligation is $36,000.

Relative percentages vs. percentage points

You may have noticed that polls measuring the favorability of each candidate are frequently cited in news articles regarding elections in the USA for members of the parliament, the premier, or the president of a town, municipality, or the entire country. Often, percent points rather than percentages will be used to illustrate differences in sentiment and changes in the aforementioned polling metrics. A percentage-based “percent point” resembles an absolute difference.

This mode of our % difference calculator does not handle such computations, which only apply when comparing differences in percentage measures. For instance, the support for candidate A might have been 40% prior to a particular political event but only 35% afterwards. Simply subtracting 35 percent from 40 percent results in a change of 5 percentage points (but is a percentage change of 12.5 percent).