How do you calculate index?

To calculate an index, you typically select a base period and a set of items or data points. The index value is derived by comparing the current period's value to that of the base period, often using the formula: Index = (Current Period Value / Base Period Value) × 100. This results in a percentage, where a value above 100 indicates an increase compared to the base period, and a value below 100 indicates a decrease. Adjustments may be made for factors like inflation or weighting of different components, depending on the type of index being calculated.