By Zencalcy Editorial TeamLast reviewed About us
Measure before-and-after change: enter the original value and the new value to get the signed percentage with its direction labeled automatically — increase, decrease, or no change.
Directional increase or decrease between an old and a new value.
Change % = ((New − Old) / |Old|) × 100
Dividing by |Old| keeps the sign meaningful for negative baselines; an Old value of zero is rejected as undefined.
| Symbol | Meaning |
|---|---|
| Old | Original value (cannot be zero) |
| New | Value after the change |
Price rises from 100 to 120 → +20% increase. Salary drops from 5000 to 4500 → 10% decrease.
Continue with the Percentage Calculator, all math calculators, or browse the full calculator directory.
Change is directional (before → after, base = old). Difference is symmetric (base = average). Use Percentage Difference for non-sequential comparisons.
Click to use the Absolute Value Calculator and get instant results.
Click to use the Basic Calculator and get instant results.
Click to use the Scientific Calculator and get instant results.
Click to use the Exponent Calculator and get instant results.
Click to use the Square Root Calculator and get instant results.
Click to use the Cube Root Calculator and get instant results.
Content updated: September 2026