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The total fatty matter (TFM) is one of the most important characteristics describing the quality of soap and it is always specified in commercial transactions. It is defined as total amount of fatty matter, mostly fatty acids, that can be separated from a sample after splitting with mineral acid, usually HCl. This is the method and idea that we used here to determine the total fatty matter in soaps. Soaps are graded in terms of total fatty matter. TFM is usually associated with hardness and lower quality of soaps.

TFM is a measure of identifying the amount of fatty matter present in soap. Bureau of Indian Standards (BIS) has categorized bath or toilet soaps as ‘normal’, ‘baby, transparent, and antibacterial soaps. The last three are called specialty soaps targeted to specific users. A toilet soap is a cosmetic by law and it must fulfill the requirements of the relevant Indian standard.

BIS categorized toilet soaps in to three grades based on the total fatty matter present in them.

TFM is above 76%, grade I, which is having good quality.

TFM above 60%, belongs to grade II and TFM above 50% belongs to grade III.

According to International Standards (ISO), good quality soaps must have TFM above 76%.

This calculator calculates the total fatty matter (tfm) using weight of the china dish, soap after drying, soap sample values.