Percentage Change Calculator
Calculate the percentage increase or decrease between any two values. Enter the original and new value to instantly see the percentage change, absolute difference, and multiplier.
How to Use This Calculator
- Enter the original (starting) value — the number you’re measuring from
- Enter the new value — the number you’re measuring to
- Click Calculate to see the percentage change, absolute difference, and direction
- Use the reverse section to find a new value given a starting value and a known percentage change
Find the Percentage Change
Reverse: Find the New Value
Know the starting value and the percentage change? Find the resulting value.
📐 The Percentage Change Formula
Percentage Change = ((New − Original) ÷ |Original|) × 100
- A positive result = percentage increase (e.g. +25%)
- A negative result = percentage decrease (e.g. −12.5%)
- The denominator uses the absolute value of the original so negative originals work correctly
- Example: Price rises from $80 to $100 → ((100 − 80) ÷ 80) × 100 = 25% increase
📊 Common Percentage Change Examples
| Scenario | Original | New | Change |
|---|---|---|---|
| Salary raise | $50,000 | $55,000 | +10.00% |
| Stock price drop | $120 | $90 | −25.00% |
| Weight change | 200 lbs | 185 lbs | −7.50% |
| Monthly revenue | $8,400 | $11,760 | +40.00% |
⚠️ Percentage Change vs. Percentage Points
These two terms are often confused:
- Percentage change: how much something changed relative to its original value. If a tax rate goes from 20% to 25%, that's a 25% increase in the tax rate itself.
- Percentage points: the raw arithmetic difference. That same change is a 5 percentage point increase.
- Media and politicians frequently mix these up — always check which one is being used.
Frequently Asked Questions
What is the formula for percentage change?
Percentage Change = ((New Value − Original Value) ÷ |Original Value|) × 100. A positive result is a percentage increase; a negative result is a percentage decrease. The absolute value in the denominator ensures the formula works correctly when the original value is negative.
What is the difference between percentage change and percentage points?
Percentage change measures how much something changed relative to its starting value. Percentage points measure the raw arithmetic difference between two percentages. For example, if an interest rate rises from 2% to 3%, that is a 1 percentage point increase but a 50% percentage change in the rate.
Can the original value be zero?
No. When the original value is zero, percentage change is undefined because you would be dividing by zero. In that case, you can only report the absolute difference (New − Original), not a meaningful percentage.
How do I calculate a percentage increase from 50 to 75?
Percentage Change = ((75 − 50) ÷ 50) × 100 = (25 ÷ 50) × 100 = 50%. The value increased by 50%.
How do I find the new value after a percentage decrease?
Multiply the original value by (1 − percentage/100). For example, a 20% decrease on 500: 500 × (1 − 0.20) = 500 × 0.80 = 400. Use the Reverse section of this calculator to do this automatically.
What does a multiplier of 1.25x mean?
A multiplier of 1.25x means the new value is 1.25 times the original, which corresponds to a 25% increase. A multiplier below 1 (e.g. 0.80x) means a decrease — in this case a 20% decrease.