A sliding scale is a pricing method that adjusts the cost of goods or services based on certain criteria, such as income level or usage. This means that the price charged for an item or service may vary depending on factors other than standard fixed prices. For example, a healthcare provider might use a sliding fee scale to offer discounted rates to patients who have lower incomes or limited resources. In this case, the more money a patient makes, the higher their bill will be, and vice versa. The term "sliding scale" can also refer to a range of values that change gradually over time, such as a stock index or commodity prices.