The economic, social and environmental costs of food waste are being increasingly recognised. Food waste consists of both edible and inedible components. Whilst wastage of edible food is problematic for obvious reasons, there are also costs associated with the disposal of the inedible fraction to landfill. This is the third in a series of papers examining the costs of food waste throughout the value chain in South Africa. The previous papers focused on the edible portion of food waste. In this paper, costs associated with inedible food waste in South Africa are estimated, in terms of the value foregone by not recovering this waste for use in downstream applications, such as energy generation or composting; as well as costs associated with disposal to landfill. Opportunity costs are estimated at R6.4 (US$0.64) billion per annum, or R2668 (US$266) per tonne. Adding this to the previous estimate for edible food waste of R61.5 billion per annum (in 2012 prices; equivalent to R65 billion in 2013 prices) results in a total opportunity cost of food waste in South Africa (in terms of loss of a potentially valuable food source or resource) of R71.4 (US$7.14) billion per annum, or R5667 (US$567) per tonne. Thereafter, estimates of the costs associated with disposal of this food waste to landfill, including both financial costs and externalities (social and environmental costs), are taken into account. These costs amount to R255 (US$25) per tonne, giving rise to a total cost of food waste in South Africa of R75 billion (US$7.5 billion) per annum, or R5922 (US$592) per tonne. This is equivalent to 2.2% of South Africa's 2013 GDP.