Use this calculator to help you with problems involving percentage increase and decrease.
Take a look at these examples to see how percent change is calculated.
Calculating Percent Increase
Example #1
The formula for percent increase is:
\(\dfrac{\text{new value}-\text{original value}}{\text{original value}}\)
To start, lets determine how much the value has increased by subtracting the original value from the new value.
\(60-50=10\)
Then, we divide the increase by the original value, which gives us the increase as a decimal.
\(10\div 50=0.2\)
Finally, convert the decimal to a percentage by multiplying by 100.
\(0.2 \times 100 = 20\)
Therefore, the price increased by 20%!
Example #2
The formula for percent increase is the same, even when working with decimals:
\(\dfrac{\text{new value}-\text{original value}}{\text{original value}}\)
First, we need to find the amount of increase by subtracting the original value from the new value.
\(95.5-80=15.5\)
Then, we need to divide the increase by the original value.
\(15.5 \div 80 = 0.19375\)
Finally, we can convert the decimal to a percentage:
\(0.19375 \times 100 = 19.375\)
Therefore, the score increased by 19.375%!
Calculating Percent Decrease
Example #1
The formula for percent decrease is:
\(\dfrac{\text{original value}-\text{new value}}{\text{original value}}\)
To start, we need to find how much the value has decreased by subtracting the new value from the original value.
\(40-30=10\)
Then, we need to divide the decrease by the original value.
\(10\div 40=0.25\)
Finally, we can convert the decimal to a percentage.
\(0.25 \times 100 = 25\)
Therefore, the price decrease by 25%!
Example #2
The formula for percent decrease is:
\(\dfrac{\text{original value}-\text{new value}}{\text{original value}}\)
To start, we need to find how much the value has decreased by subtracting the new value from the original value.
\(16,500-15,900=600\)
Then, we need to divide the decrease by the original value.
\(600\div 16,500\approx 0.03636\)
Finally, we can convert the decimal to a percentage.
\(0.03636 \times 100 \approx 3.64\)
Therefore, the price decrease by approximately 3.64%!
