How to Calculate Percentage Increase

Whenever a statistic or measurement increases, it is possible to calculate the percent of that increase. Calculating percentage increase is not difficult if you know the basic formula to use. In fact, by learning this basic math skill, you can look smart and educated among your friends.

1
Figure out what your original amount and increased amount are. If the problem reads, "Last week 345 people attended church. This week there were 360 people at church. What is the percentage increase?" You will need to add, using 345 as your original amount and 360 as your increased amount.
2
Find the difference between the two numbers to find how much the total increase is. To do this, subtract 345 from 360. This gives you 15. This is the amount of the increase.
3
Figure out what percent 15 is of the original amount. Use this formula: amount of increase = original amount * percent increase. Since you do not know the percentage increase, plug in the values you do know and leave that as the variable. This looks like 15 = 345 x.
4
Solve for x. Round your answer to the nearest thousandth: 15 divided by 345 is .043.
5
Change your answer to percentage form by moving the decimal to the right two places and adding the percent sign. The percentage increase in this example is 4.3%.
6
Check your answer: .043 * 345 = 14.835. This is not exactly 15 because we rounded our percentage answer, but it is close, which indicates that we did the problem correctly.
7
Simplify these steps into the following formula: (increased amount - original amount) / original amount. This would look like (360 - 345)/345. The answer is still 4.3%.