Find Percentage Change
Enter original and new values to calculate the % change
Examples:
How to Calculate Percentage Increase & Decrease
Percentage change tells you how much a value has grown or shrunk relative to its original size. A positive result means an increase; a negative result means a decrease.
Percentage Increase Formula
% Increase = ((New Value − Original Value) ÷ Original Value) × 100
Percentage Decrease Formula
% Decrease = ((Original Value − New Value) ÷ Original Value) × 100
Real-World Examples
💰 Salary Raise
Salary went from $50,000 to $55,000:
(55,000 − 50,000) ÷ 50,000 × 100 = 10% increase
(55,000 − 50,000) ÷ 50,000 × 100 = 10% increase
🛍️ Price Discount
Item dropped from $120 to $90:
(120 − 90) ÷ 120 × 100 = 25% decrease
(120 − 90) ÷ 120 × 100 = 25% decrease
📈 Stock Price
Stock rose from $45 to $63:
(63 − 45) ÷ 45 × 100 = 40% increase
(63 − 45) ÷ 45 × 100 = 40% increase
⚖️ Weight Loss
Weight went from 180 lbs to 162 lbs:
(180 − 162) ÷ 180 × 100 = 10% decrease
(180 − 162) ÷ 180 × 100 = 10% decrease
Percentage vs Percentage Points
These are NOT the same. If a tax rate rises from 20% to 25%, that is a 5 percentage point increase, but a 25% percentage increase in the rate itself (5 ÷ 20 × 100 = 25%).
When to Use Each Calculation Mode
- Find % Change: When you have both values and want to know how much it changed relatively — price comparisons, salary changes, test score improvements, population growth
- Find New Value: When you know the starting value and the % change — applying a 15% raise to a salary, calculating a 20% discount on a price, estimating inflation impact
- Find Original Value: When you have the final value and the % applied — what was the original price before a 30% markup, what was last year's revenue before 10% growth
Percentage Increase vs Percentage Decrease
Both use the same formula structure. The only difference is the direction:
- Percentage increase: New value is larger than original → positive result → green indicator
- Percentage decrease: New value is smaller than original → negative result → red indicator
- No change: New value equals original → 0% → neutral indicator
The formula uses the absolute value of the original in the denominator — this handles negative original values correctly (e.g., temperatures below zero, negative financial balances).
Common Percentage Increase Examples
- Salary raise: $50,000 to $55,000 → 10% increase
- Price hike: $1.20 to $1.44 per litre → 20% increase
- Population growth: 1,000,000 to 1,050,000 → 5% increase
- Stock gain: $45 to $63 per share → 40% increase
- Website traffic: 2,400 to 3,000 monthly visitors → 25% increase
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