Percentage difference is calculated using the formula |x_known - x_exp| / x_known * 100, where x_known is the known value and x_exp is the experimental value. This calculation helps quantify the deviation between two values, providing insights into data accuracy and variability. It is commonly utilized in data analysis to assess the reliability of experimental results compared to established benchmarks. Understanding percentage difference is essential for researchers and analysts to communicate the significance of their findings effectively. Accurate calculation of percentage difference enhances data interpretation and decision-making processes.