AVERAGE PHYSICAL PRODUCT: The quantity of total output produced per unit of a variable input, holding all other inputs fixed. Average physical product, usually abbreviated APP, is found by dividing total physical product by the quantity of the variable input. Average physical product is actually just another name for average product (AP). But don't be confused by the extra term (physical). See also | total product | variable input | fixed input | total physical product | average product | average revenue product | marginal productivity theory | factor markets | marginal physical product | marginal revenue product | law of diminishing marginal returns |