Percentage Change – Free Online Calculator

Percentage Change is a free online calculator from Toolinza. Calculate percentage increase or decrease. It runs entirely in your browser — your data is never uploaded — needs no signup, and works on any device. Toolinza offers 293+ free tools used by people across the UK, USA, Canada, Australia, the EU, India, Pakistan, the Middle East and worldwide.

About the Percentage Change

Percentage change is how we describe almost every rise and fall — a price increase, a pay rise, a drop in traffic, an investment return. The formula is simple but easy to apply the wrong way round, which flips your answer.

This Percentage Change calculator works out the increase or decrease between two values as a percentage, so you always get the direction and size right.

How to use the Percentage Change

Enter the original (starting) value.
Enter the new value.
The tool compares them.
See the percentage increase or decrease.

Key features of the Percentage Change

Calculates percentage increase and decrease
Shows the direction and size of change
Works for prices, stats and returns
Instant, accurate result
Private — calculated in your browser

How the Percentage Change works

Each calculator applies the standard mathematical formula for its task — whether that is percentages, areas and volumes, averages, ratios or date arithmetic — following conventional order of operations and calendar rules (including leap years where relevant). Calculations run in your browser and update instantly.

Tips & best practices

Always divide by the original value, not the new one — dividing by the wrong base is the most common mistake.
A rise then an equal-percentage fall does not return to the start, because the second percentage is of a different base.
A negative result simply means a decrease.

Standards & accuracy

Applies standard mathematical formulas and conventions for accurate, verifiable results.

Results follow standard mathematical conventions. For very large or high-precision scientific work, be mindful of normal floating-point rounding, as with any digital calculator.

Who uses the Percentage Change?

Measuring a price rise or discount
Working out an investment return
Tracking growth or decline in stats
Comparing before-and-after figures

Privacy & security

The Percentage Change runs entirely inside your web browser. Your data — whether that is a file, figures or text — is processed on your own device and is never uploaded to a server, stored or shared. There is no signup and no account, so you can use it as often as you like while keeping full control of your information. This makes it a safe choice even for confidential and sensitive work.

Why choose Toolinza?

100% free — no hidden charges, watermarks or usage caps.
Private & secure — your data stays on your device.
Standards-compliant — accurate results suitable for the UK, USA, Canada, Australia, EU, India, Pakistan, the Middle East and worldwide.
Works everywhere — desktop, tablet and mobile.

Frequently asked questions

Subtract the original value from the new value, divide by the original value, then multiply by 100. The calculator does this and shows whether it is an increase or decrease.

Percentage change is always relative to the starting point, so the original value is the base. Dividing by the new value gives the wrong answer.

A negative percentage indicates a decrease from the original value, while a positive one indicates an increase.

Yes. The Percentage Change is completely free with no signup, no watermarks and no usage limits. Toolinza is supported by unobtrusive advertising so every tool stays free.

Absolutely. This tool runs entirely in your browser — your data and files are never uploaded to any server, so everything stays private on your own device.

No. The Percentage Change works instantly in any modern web browser on desktop, tablet and mobile — Windows, macOS, Linux, Android and iOS.