Percentage Change Between Two Numbers
Find the percentage change between two numbers in one step. The calculator shows a signed result (+ for growth, − for a drop), the absolute change, and the symmetric percent difference used in science and statistics.
- Percent change
- -25%
- Direction
- Decrease
- Percent difference (symmetric)
- 28.5714%
- Absolute change
- -20
Steps
- (60 − 80) ÷ |80| × 100 = -25%
Worked example
Example: monthly sales fell from 80 to 60 units
- Change = 60 − 80 = −20
- −20 ÷ 80 = −0.25
- −0.25 × 100 = −25%
Sales changed by −25% (a 25% decrease).
Formula
Percent change = (New − Old) ÷ |Old| × 100
Percent difference = |A − B| ÷ ((A + B) ÷ 2) × 100
Use percent change when one value clearly comes first (before/after). Use percent difference when you are comparing two values with no natural order, such as two lab measurements.
Frequently asked questions
What's the formula for percentage change?
Percentage change = (new value − old value) ÷ old value × 100. A positive result is an increase and a negative result is a decrease.
Why is a 50% drop followed by a 50% gain not break-even?
Each percentage is measured from a different base. 100 → 50 is −50%, but 50 → 75 is +50%, leaving you at 75.
How do I handle negative numbers?
Divide by the absolute value of the old number. Going from −50 to −25 is (−25 − (−50)) ÷ 50 × 100 = +50%.
Last reviewed October 17, 2026 · Calculations run in your browser; nothing you enter is sent to a server.