How this tool works
Percentage of value = value × rate ÷ 100. Percentage change = (new − old) ÷ old × 100. A positive result is an increase; a negative result is a decrease.
Privacy and editorial review
This tool runs in your browser and does not require an account. GrowthSparx reviews its logic and explanatory content, but you should verify outputs before production use.
Frequently asked questions
How is percentage change calculated?
Subtract the old value from the new value, divide by the old value, then multiply by 100.
Can the calculator show a decrease?
Yes. When the new value is lower than the old value, the percentage-change result is negative.
What happens when the old value is zero?
Percentage change is undefined when the old value is zero, so the tool shows a dash.