Use this calculator for public, academic, or special library data. Using inflation-adjusted data in your advocacy will have a stronger impact than showing the change in dollar value alone. Adjusting for inflation takes into account the rising cost of library management over time. Using per capita data additionally expresses what this revenue means in per person spending ability from year to year. This calculator takes data about past and current library money (revenue, state aid, etc.) and adjusts for inflation by converting the historic data to the most current year's data. It also calculates the percentage difference between the inflation-adjusted values and calculates per capita revenue. See the bottom of the page to learn how this is calculated.