Percentage Change Calculator
Enter the original value and the current value, then calculate the absolute change and percentage change.
What is a Percentage Change Calculator?
A Percentage Change Calculator is an online tool that calculates the percentage difference between two values. Simply enter the original value (baseline) and the new value to get both the absolute change and the percentage change. This tool also works as a general-purpose percent calculator or ratio calculator for comparing any two numbers.
How to Use the Percentage Change Calculator
- Enter the Original Value (the baseline number, such as yesterday's price)
- Enter the Current Value (the new number to compare)
- Click "Calculate" to instantly get the change amount and percentage
- Results are automatically rounded to 3 decimal places; positive = increase, negative = decrease
Use Cases
- Stock Price Change：Calculate the percentage increase or decrease between opening and closing prices.
- Investment Returns：Measure portfolio growth or fund NAV changes over time.
- Sales & Revenue Growth：Compare sales figures month-over-month or year-over-year.
- KPI Tracking：Track changes in key metrics like website traffic, conversion rates, or customer acquisition.
- General Percent Calculator：Calculate the percentage difference between any two numbers for everyday comparisons.
Why Use This Tool?
- 100% browser-based calculation - your data never leaves your device
- No registration or login required - instant access
- Precise results with 3 decimal places for accurate analysis
- Shows both absolute change and percentage for easy verification
Percentage Change Formula
Percentage Change = ((New Value - Original Value) / Original Value) × 100%
Example Calculation
If a stock closed at $100 yesterday and $110 today:
Percentage Change = (110 - 100) / 100 × 100% = 10%
Frequently Asked Questions
What is percentage change and how is it different from percentage points?
Percentage change measures the relative difference between two values as a percentage. For example, going from 100 to 120 is a 20% increase. Percentage points, on the other hand, measure the absolute difference between two percentages (e.g., from 10% to 15% is an increase of 5 percentage points).
What is the formula for calculating percentage change?
The percentage change formula is: ((New Value - Original Value) / Original Value) × 100%. For example, if the original value is 100 and the new value is 120: ((120-100)/100) × 100% = 20% increase.
Can I use this as a general percent calculator?
Yes! This tool works as a versatile percent calculator. You can calculate the percentage difference between any two numbers, making it useful for price comparisons, grade calculations, or any scenario where you need to find the relative change.
Can I calculate ratio changes with this tool?
Absolutely. The percentage change is essentially a ratio comparison expressed as a percentage. Enter your original and new values, and the tool calculates the ratio of change between them.
How many decimal places are shown in the results?
Results are rounded to 3 decimal places using standard rounding rules. For example, 10.1457% would display as 10.146%.
Why can't I calculate when the original value is 0?
The percentage change formula requires dividing by the original value. Since division by zero is undefined in mathematics, the calculator displays "N/A" when the original value is 0.
Is my data saved or sent to a server?
No. All calculations happen locally in your browser. Your data is never sent to any server or stored anywhere. When you close the page, all input data is gone.