Percentage Change Calculator
Calculate the percentage increase or decrease between two values.
A percentage change calculator measures how much a value increased or decreased as a percentage of its original value.
How to Use the Percentage Change Calculator
- Enter old value. Type the starting value.
- Enter new value. Type the ending value.
- Read the change. See the percentage increase or decrease.
This tool processes your input locally in your browser. Nothing is uploaded.
What Is Percentage Change?
Percentage change measures the relative growth or decline between two values, commonly used for prices, revenue and statistics.
Formula
Percentage change = ((new − old) / |old|) × 100. A positive result is an increase; a negative result is a decrease.
Key Features
- Increase/decrease calculation
- Uses absolute old value
- Instant results
Examples
- From 100 to 150 is a 50% increase.
- From 100 to 80 is a 20% decrease.
Common Use Cases
- Price changes
- Growth metrics
- Budget analysis
Tips & Best Practices
- A decrease from 100 to 50 is −50%, and recovering to 100 is a 100% increase.
Limitations
- Percentages do not reverse symmetrically (a 50% drop needs a 100% rise to recover).
Related Tools
Related Articles
Percentage Change Calculator – Complete Guide & Free Online Tool A percentage change calculator measures how much a value increased or decreased as a percentage of its original value. Free online tool included. Read guide → Discount Calculator – Complete Guide & Free Online Tool A discount calculator tells you how much you save and the final price after applying a percentage discount to an item. Free online tool included. Read guide → Tip Calculator – Complete Guide & Free Online Tool A tip calculator computes the tip and total, and can split the amount evenly among any number of people. Free online tool included. Read guide → BMI Calculator – Complete Guide & Free Online Tool A BMI calculator computes your Body Mass Index from your weight and height and places it into a standard category (underweight, normal, overweight, obese). Free online tool included. Read guide →
Frequently Asked Questions
What is percentage change?
The relative difference between two values as a percentage of the original.
What is the formula?
((new − old) / |old|) × 100.
Is it free?
Yes, and it runs locally.