EVERYDAY / CALCULATOR
Percentage Change Calculator.
Calculate the increase or decrease between two values.
LET’S WORK IT OUT
Your numbers, your answer.
THE WHY BEHIND THE ANSWER
How it works.
The starting value is the reference. A positive result is an increase; a negative result is a decrease.
THE FORMULAPercentage change = (new value − starting value) ÷ starting value × 100
Worked example
From 80 to 100: (100 − 80) ÷ 80 × 100 = 25%.
Good to know
This calculator requires a positive starting value. Percentage change from zero is undefined.
ONE MORE THING
Why do increases and decreases use different percentages?
Each percentage uses its own starting value. Going from 80 to 100 is a 25% increase, while returning from 100 to 80 is a 20% decrease.