Business maths tool
Percentage Change Calculator
Compare an old value and a new value to see the percentage increase or decrease clearly. Useful for price changes, costs, sales, traffic, and quick business reporting.
Percentage change tool
Compare two values and see both the absolute change and the percentage difference.
Absolute change
20.00
Percentage change
20.00%
Quick notes
- • Percentage change depends on the starting value, so the old number matters.
- • A positive result means an increase and a negative result means a decrease.
- • Keep the original numbers beside the result so the change stays easy to interpret.
Need more context?
How to calculate percentage change
A simple guide to working out increases and decreases without getting lost in the formula.
Read guideWhat this calculator helps you do
Check price changes quickly
Useful when a product or service price has gone up or down and you want to understand the scale of the change properly.
Review business performance
This can help when comparing revenue, costs, orders, enquiries, traffic, or any other number that changes over time.
Sense-check reporting
It is a fast way to confirm whether a reported increase or decrease actually matches the figures underneath it.
Worked examples
Example 1: price increase
If a price moves from £200 to £250, the change is £50.
Divide that change by the original £200 and the result is a 25% increase.
Example 2: cost decrease
If a monthly cost drops from £500 to £425, the change is -£75.
Divide -£75 by the original £500 and the result is a 15% decrease.
Common mistakes to avoid
- Using the new value as the base instead of the original value.
- Confusing the absolute change with the percentage change.
- Mixing up a percentage change with a percentage-point change.
- Looking only at the percentage and forgetting the real-world size of the original numbers.
Who this is for
- Small businesses checking price or cost movement.
- Freelancers reviewing rates, revenue, or expenses.
- Anyone preparing a simple update or report.
- Anyone who wants a fast business maths check without using a spreadsheet.
Quick tip
Keep both the old value and the new value beside the final percentage. That makes the result much easier to explain and stops the number being taken out of context.
Read the guide or open the starter pack
Use the guide for a plain-English explanation of the maths, or open the free starter pack for quick-reference business pricing support.