Percentage Change Calculator: Increase, Decrease and Formula
Learn the percentage change formula with increase and decrease examples, and avoid common denominator mistakes.
A Percentage Change Calculator measures how much a value has increased or decreased relative to its original value.
Percentage Change Formula
Percentage Change = (New Value тИТ Old Value) ├╖ Old Value ├Ч 100
A positive result means an increase; a negative result means a decrease.
For example, if a price changes from тВ╣800 to тВ╣1,000, the change is тВ╣200. Dividing тВ╣200 by тВ╣800 and multiplying by 100 gives a 25% increase. If it changes from тВ╣1,000 to тВ╣800, the result is a 20% decrease.
How to Use the Calculator
- Enter the original value.
- Enter the new value.
- Calculate the percentage change.
- Check that the original value is not zero, because division by zero is undefined.
Percentage Change vs Percentage Difference
Percentage change uses a specific starting value as the baseline. Percentage difference is often used to compare two values without designating one as the original and may use their average as the denominator. They answer different questions.
Where It Helps
You can compare price changes, monthly expenses, sales, marks, business metrics, or other values measured consistently over time.
Common Mistakes
- Using the new value as the denominator instead of the original value.
- Forgetting the sign of the result.
- Comparing values with different units or periods.
- Assuming a 20% decrease followed by a 20% increase returns to the original value; it does not.
Use percentage change to describe a past movement, not to predict what will happen next.
Explore More on Calcusite AI
Use the relevant calculator on Calcusite AI to test different values and compare scenarios. Results are estimates based on the inputs and assumptions you provide.