General
Percentage Change Calculator
Calculate the percentage difference between two values, or apply a percentage change.
How It Works
The percentage change formula is: ((New Value − Old Value) ÷ Old Value) × 100. A positive result means an increase; negative means a decrease.
For example, if a price goes from $80 to $100, the percentage change is ((100 − 80) ÷ 80) × 100 = 25% increase. If it drops from $100 to $80, it's ((80 − 100) ÷ 100) × 100 = 20% decrease.
Note: percentage increase and decrease are not symmetrical — a 25% increase followed by a 20% decrease returns you to the original value, not a 25% decrease.
Frequently Asked Questions
How do I calculate percentage increase?
Use the formula: ((New Value − Original Value) ÷ Original Value) × 100. For example, a salary increase from $80,000 to $85,000 is a ((85,000 − 80,000) ÷ 80,000) × 100 = 6.25% increase.
How do I calculate a discount percentage?
Discount percentage = ((Original Price − Sale Price) ÷ Original Price) × 100. For example, an item reduced from $200 to $150 has a discount of ((200 − 150) ÷ 200) × 100 = 25%.
What is the difference between percentage change and percentage points?
Percentage change is relative (e.g., interest rates rising from 2% to 3% is a 50% increase). Percentage points measure the absolute difference (1 percentage point). These are very different — always clarify which you mean.
How do I calculate a markup percentage?
Markup = ((Selling Price − Cost Price) ÷ Cost Price) × 100. If you buy something for $50 and sell for $75, your markup is ((75 − 50) ÷ 50) × 100 = 50%. Note that margin and markup are different calculations.
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Last updated: April 2026
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