This report presents empirical formulae and computer programs which can be used to calculate binaural and monaural percentage loss of hearing (PLH) accurately in hearing threshold level (HTL) steps as small as 0.5 dB or less. Binaural and monaural PLH tables are also presented which differ slightly from the 1974/76 tables but which give the same results as the computer programs. PLH determined by means of these new tables is at least as good a predictor of hearing difficulties in everyday life as PLH determined by means of the 1974/76 tables. The slight change in the PLH tables and publication of the International Standard ISO 7029 concerning the effects of ageing on HTL have made it necessary to prepare a revised presbyacusis correction table. Separate values of age-related PLH are required for males and females since hearing deteriorates faster as a result of ageing in men than in women. The frequency range of the new binaural and monaural PLH tables is 500 to 4000 Hz, the same as that of the 1974/76 tables, and it is recommended that this range be used for general purposes. However, there are special circumstances where a set of tables which cover the frequency range 500 to 8000 Hz are required. Tables which extend the frequency range of the PLH procedure to 8000 Hz have been prepared and are also presented in this report. This procedure is now used in all States and Territories of Australia. The accompanying user-friendly Windows software available on CD enables users to obtain the percentage of hearing loss without having to look up the tables in NAL Report 118.