Compute the change between two values

Compute the change between two values. Handy for students, analysts and engineers checking a calculation or conversion before using the result.

Compute the change between two values. The answer appears right away in your browser and is ready to use, with no account, upload or stored data.

How to use

Type the starting value into the first field.
Enter the ending value into the second field.
Run the calculation to get the percentage change.
Clear both fields when you want to test another pair of values.

Example

An analyst compares newsletter subscribers from one month to the next. The first number is 120 and the later number is 150. After running the calculation, the analyst reads the percentage change and uses it to describe the trend in a report. The figure is then checked against the monthly totals.

Input

120
150

Limits and formats

The result describes movement between two values, not a percentage of one value.
A starting value of zero prevents a standard percentage change calculation.
A negative result usually means a decrease, while a positive result means an increase.
Swapping the two values changes the meaning and the result.
Very small changes can be hard to interpret without the original context.

Where processing happens

Both values are handled inside your browser, and the change is computed on your device. No number or file is sent away from the page. The answer is displayed locally and is not retained after you leave.

Frequently asked questions

What if the starting value is zero?

A standard percentage change cannot be calculated from zero because division by zero is undefined. The tool may show an error or an unusable figure. In that situation, compare absolute differences instead of relying on a percentage.

How should I read a negative change?

A negative percentage means the ending value is lower than the starting value. The larger the absolute number, the bigger the drop. A positive percentage means the value rose.

Can I compare percentages with this tool?

You can enter percentages as the two values, but the output is still a percentage change between them. That can be confusing when your inputs are already rates. Decide what question you are answering before trusting the figure.