Free percent increase & decrease calculator — get the result and formula instantly
Percentage change measures how much a value has shifted from its original amount, expressed as a percentage. The formula is: (New Value − Original Value) ÷ Original Value × 100. Here's how it works: first, find the difference between your new and original values; then divide that difference by the original value; finally, multiply by 100 to convert to a percentage. A positive result indicates growth, while a negative result shows a decline. For example, if a price increases from $50 to $75, the calculation is: (75 − 50) ÷ 50 × 100 = 50%. This means the price went up by 50%. Percentage change is essential in finance, retail, economics, and data analysis for understanding trends and comparing relative changes across different values. Whether you're tracking salary increases, stock performance, or business metrics, this formula provides a standardized way to measure change.
The percentage change formula is:
For percentage difference (comparing two values without direction), the formula is:
Percentage change comes up constantly in finance, shopping, work, and everyday life. Here are the most common situations where people use this calculator.
A share you bought at £120 is now trading at £98.
Your holding has lost 18.33% of its value.
Your salary goes from £32,000 to £35,500 after a raise.
A pay rise of just under 11%.
A jacket was £85, now marked down to £59.
Over 30% off — worth checking if it's a genuine deal.
Monthly electricity cost rose from £110 to £147.
A third more expensive than last year.
A property bought for £240,000 is now valued at £310,000.
Nearly 30% appreciation in value.
A business made £8,400 in March and £11,200 in April.
Strong month-on-month growth of a third.
Percentage change is a way to express how much a value has increased or decreased relative to its original amount. It's calculated by finding the difference between the new and original values, dividing by the original value, and multiplying by 100. The result shows the relative change as a percentage.
To calculate percent increase, subtract the original value from the new value, divide the result by the original value, and multiply by 100. For example, if a value increases from 40 to 50, the calculation is: (50 − 40) ÷ 40 × 100 = 25% increase.
Percent decrease is calculated the same way as percent increase, but the result will be negative. Subtract the new value from the original value, divide by the original value, and multiply by 100. For example, if a value decreases from 60 to 45, the calculation is: (45 − 60) ÷ 60 × 100 = −25% decrease.
Percent change measures the change from an original value to a new value, showing direction (increase or decrease). Percent difference compares two values without considering which is the starting point, using their average as the base. Our detailed comparison of percent change vs percent difference explains when to use each method with real-world examples.
Percentage change cannot be calculated when the original value is zero, because division by zero is mathematically undefined. In such cases, you might describe the change in absolute terms rather than as a percentage. To better understand how percentage change works across different scenarios, check out our percentage change examples with step-by-step solutions.
Percentage change is critical in business and finance for tracking revenue growth, analyzing profit margins, monitoring sales trends, and evaluating stock performance. Learn how professionals use this metric in our guide to percentage change in business and finance with real company examples.