Calculator
Percentage Change Calculator
Find the percent increase or decrease from an old value to a new value.
Result
Percentage change
25%
Absolute change
20
How to use this calculator
What this calculator does
Find the percent increase or decrease from an old value to a new value.
How to use it
Enter the starting value and ending value. Read the sign of the result first, then the size of the percentage change relative to the starting value.
What the result means
Use the result as a direct calculation from the values you entered. If it looks off, check the inputs and formula shown on this page.
Browse more math calculators for related estimates and comparisons.
Math calculators follow the formulas shown on each page. Check your inputs if a result looks unexpected.
Scenario guidance
When to use this
Use this when you need to compare an old number with a new number and express the difference as a percent increase or decrease.
Example scenario
A shopper is comparing a price that moved from $80 to $100 and wants to know the percentage increase.
Inputs that usually matter most
- Old value, because it is the starting point for the comparison.
- New value, because it shows where the number ended up.
- Whether the old value is positive, negative, or zero, since zero makes percent change undefined.
Common mistake to avoid
Do not confuse percent change with percentage points; percent change measures relative movement from the old value.
How to interpret the result
A positive result means an increase, a negative result means a decrease, and the size shows how large the change is relative to the old value. Use the original value as the reference point when explaining the result.
Formula
The result is positive for an increase and negative for a decrease. The old value is the comparison base, so it cannot be zero.
Example change
Moving from 80 to 100 is a 25% increase because the change is 20 divided by 80.
Frequently Asked Questions
Why can the old value not be zero?
Percentage change divides by the old value, so zero would make the calculation undefined.
Is percentage point the same as percent change?
No. Percentage points compare two percentages directly, while percent change measures relative movement.
Related Calculators
Loan Payment Calculator
Estimate the monthly principal-and-interest payment for a fixed-rate loan, then compare how the amount borrowed, rate, and term affect repayment pressure.
Compound Interest Calculator
Project how a starting balance may grow over time when interest or returns compound, and test how rate, time, and compounding frequency change the ending estimate.