Percentage Change Calculator
Percentage increase or decrease between two numbers
Percentage Increase
Working
- % change = (new − old) ÷ |old| × 100
- = (300 − 250) ÷ 250 × 100 = 20%
- 1Choose what to find% change, or apply a %
- 2Enter the valuesOld and new, or a number and %
- 3See the resultWith the working
How is percentage change calculated?
Percentage change compares the difference with the starting value, so the same difference is a bigger percentage on a smaller start.
% change = (new − old) ÷ old × 100
Increase by p% = x × (1 + p ÷ 100) · Decrease by p% = x × (1 − p ÷ 100)
Up and down aren't symmetric
A 20% rise followed by a 20% fall doesn't get you back: 100 → 120 → 96. To undo a 20% rise you need a 16.7% fall.
Percentage points
When the values are themselves percentages, say so carefully: an interest rate going from 8% to 10% is a rise of 2 percentage points, or a 25% increase.
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Frequently asked questions
What is the percentage increase from 250 to 300?
20%: (300 − 250) ÷ 250 × 100.
How do I calculate a percentage decrease?
Use the same formula; the result is negative. From 80 to 60 is (60 − 80) ÷ 80 × 100 = −25%, a 25% decrease.
How is this different from percentage difference?
Percentage change measures against the starting value. 'Percentage difference' compares two values against their average, used when neither is the start.
Last reviewed: October 2026