How to use the percent increase and decrease calculator
Compute percent change between two values. Enter old value, new value in the fields above; the percent change, difference are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “percentage increase”, “percent decrease”, “growth percent”, “calculate percent increase and decrease”, “find percent change”.
Formula
Variables
- a — Old value
- b — New value
Worked example
With old value = 80, new value = 100, the calculator gives percent change ≈ 25 %; difference ≈ 20.
Frequently asked questions
What is the percent increase and decrease calculator used for?
Compute percent change between two values. It helps with questions such as “percentage increase”, “percent decrease”, “growth percent”.
What is the formula for the percent increase and decrease calculation?
Percent change (%) = 100 × (b-a) / a. Difference = b-a. Here a is old value, b is new value.
What inputs do I need for the percent increase and decrease calculator?
You need old value, new value. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the percent increase and decrease calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the percent increase and decrease result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.