The percentage change formula compares a new value with its original value. A positive result shows an increase, while a negative result shows a decrease.
Percentage change formula
Subtract the original value from the new value. Divide the difference by the absolute original value, then multiply by 100.
Worked example
A price rises from 80 to 100. The difference is 20. Divide 20 by 80 and multiply by 100 to get a 25% increase.
Check your answer
Use the calculator on the homepage to confirm the result and see the working.