Calculator Wizard
How Percent Change Is Calculated
Percent change measures how much a value has grown or shrunk, relative to where it started. It's directional — unlike percentage difference, which treats two values symmetrically, percent change always measures relative to a specific original value.
A positive result means an increase; a negative result means a decrease.
Worked Examples
Example 1: Price rises from $40 to $50
Step 1: Find the difference → 50 − 40 = 10
Step 2: Divide by the original → 10 ÷ 40 = 0.25
Step 3: Convert to percent → 0.25 × 100 = 25% increase
Example 2: Value drops from 80 to 60
Step 1: Find the difference → 60 − 80 = −20
Step 2: Divide by the original → −20 ÷ 80 = −0.25
Step 3: Convert to percent → −0.25 × 100 = 25% decrease
The Three Core Percentage Questions
This is one of three fundamental percentage calculations. Here's how it fits with the other two:
| Question | Formula | Tool |
|---|---|---|
| What is X% of Y? | (X ÷ 100) × Y | Percentage Calculator |
| X is what percent of Y? | (X ÷ Y) × 100 | What Percent Calculator |
| What percent change from X to Y? | ((Y − X) ÷ X) × 100 | This calculator |
Is this the same as percentage point change?
No — if you're comparing two percentages (like an interest rate moving from 4% to 5%), that's a different calculation with its own important distinction. See the dedicated Percentage Point Calculator for that specific case.
Can percent change be more than 100%?
Yes. If a value more than doubles, the increase exceeds 100%. For example, going from 10 to 25 is a 150% increase, since the value grew by one and a half times its original amount.
Comparing two percentages instead of tracking change over time?
Try the Percentage Point Calculator