Percentage Change Calculator
This tool lets you calculate the percentage increase or decrease between two numbers instantly and accurately, whether it's for tracking price changes, comparing growth over time, or measuring any kind of difference. It's particularly useful in finance, business, science, and everyday calculations. The tool is completely free and requires no sign-up or app download.
Percentage Calculators
Percentage Change
See the signed % change (increase or decrease) between two values.
The interactive percentage change calculator tool appears here
How to Calculate Percentage Change
Enter the old value, then enter the new value, and click "Calculate" to see the percentage increase or decrease instantly. The formula used is simple: Percentage Change = ((New Value − Old Value) ÷ Old Value) × 100.
For example, if a stock price rose from $50 to $75: ((75 − 50) ÷ 50) × 100 = 50% increase. If the result comes out negative, it means the value has decreased rather than increased.
Percentage Change Formula in Excel
To calculate percentage change in Excel, use the formula =(B1-A1)/A1, where A1 is the old value and B1 is the new value. Format the result cell as "Percentage" to display it correctly as a percent instead of a decimal.
Percent Change vs. Percent Difference
These two terms are often confused, but they measure different things. Percentage change compares a new value to an old, original value — it shows whether something increased or decreased, and by how much, relative to a known starting point.
Percentage difference, on the other hand, is used when neither number is considered the "original" — it treats both values equally by dividing the difference by the average of the two numbers, rather than by one specific starting value. Use percentage change when tracking something over time, and percentage difference when simply comparing two unrelated numbers.
When Do You Need a Percentage Change Calculator?
This calculator is useful for tracking how prices, sales, or salaries have increased or decreased, comparing growth or decline between two periods, measuring changes in weight, scores, or statistics, checking the percentage difference between any two numbers, or analyzing year-over-year performance in business and finance.
It's commonly used in fields like finance, chemistry, physics, and everyday business reporting, wherever a relative change between two values needs to be expressed clearly as a percentage.
Frequently Asked Questions
How do I calculate percentage change manually?
Subtract the old value from the new value, divide the result by the old value, then multiply by 100. For example, going from 200 to 250: ((250 − 200) ÷ 200) × 100 = 25% increase.
Does the calculator show if it's an increase or a decrease?
Yes, the calculator automatically shows whether the change is a percentage increase or a percentage decrease, along with the exact percentage value.
How much is 20% out of 70?
20% of 70 is calculated as (20 ÷ 100) × 70 = 14.
How do I calculate the percentage change in price?
Subtract the old price from the new price, divide the result by the old price, and multiply by 100. A positive result is a price increase, and a negative result is a price decrease.
What is the percent of change from 2 to 3?
Going from 2 to 3 is calculated as ((3 − 2) ÷ 2) × 100 = 50% increase.