A Percentage Increase and Decrease Calculator is a free online tool that helps you calculate how much a value increases or decreases as a percentage. It is useful for students, teachers, business owners, shoppers, and professionals who need to compare numbers quickly and accurately. Simply enter the original value and the new value, then calculate the percentage change to see whether the amount has increased or decreased. For example, you can use this calculator to determine changes in product prices, salaries, expenses, sales, profits, or exam scores. It saves time by performing the calculations automatically and reduces the chance of manual errors. A percentage increase shows how much a value has grown compared with its original amount, while a percentage decrease shows how much it has fallen. This tool is helpful when comparing discounts, tracking business performance, reviewing budget changes, or understanding price fluctuations. Its simple interface makes it easy to use on mobile phones, tablets, and computers without installing additional software. For accurate results, always enter the correct original and new values, because the percentage change is calculated relative to the original value. Use our free online Percentage Increase and Decrease Calculator to find percentage changes in seconds and make everyday calculations easier, faster, and more convenient.