Percentage Change Calculator

Work out the percentage increase or decrease between an old value and a new one.

Old value	80
New value	100

Old value

New value

Increase

25%

Going from 80 to 100 is a rise of 20, which is 25% of the old value.

Change: 20
New as % of old: 125%
Reverse change (new → old): -20%

From old to new

Old value80
Up 25%+20
New value100

1
Find the difference
100 − 80 = 20
2
Divide by the old value and × 100
20 ÷ 80 × 100 = 25%

About the Percentage Change Calculator

Percentage change compares the difference to where you started. A rise from 80 to 100 is +25%, but the fall back from 100 to 80 is only −20%, because the starting point changed. That's why a 50% loss needs a 100% gain to recover.

The formula

% change = (new − old) ÷ |old| × 100

Worked example

Price went from $80 to $100

100 − 80 = 20
20 ÷ 80 × 100 = 25% increase

Questions people ask

Is percentage change the same as percentage points?

No. A rate rising from 5% to 6% is +1 percentage point, but a 20% increase.

Why is the reverse change different?

It's measured against a different starting value.