Triglyceride Molecular weight calculator

Use this calculator to find the molecular weight of various fats and oils. The total percentage cannot exceed 100%

Enter the fatty acid profile (% weight) of your vegetable oil or animal fat or select a feedstock to start with

Triglyceride feedstock

Weight (%)

Caprylic (8:0)   Linoleic(18:2)
Capric (10:0)   Linolenic (18:3)
Lauric (12:0)   Arachidic (20:0)
Palmitic (16:0)   Behenic (22:0)
Palmitoleic (16:1)   Erucic (22:1)
Stearic (18:0)   Docosahexanoic(DHA)
Oleic (18:1)    Lignoceric(24:0)

Total weight %

Average molecular weight =

How does the calculator work?

The molecular weight of a particular fat or oil depends on its fatty acid profile. Fatty acid profile is the relative proportion of different fatty acids in an oil or fat.  In order to determine the fatty acid profile, the oil is usually converted into alcohol esters of fatty acid and then their proportionate weight is measured using gas chromatography. The relative proportions of the esters are then converted back to corresponding amounts of fatty acids. The fatty acids of animal and plant origin are all straight carbon chains differing mainly in chain length and the number of double bonds (saturation). A saturated fatty acid chain with ‘n’ number of carbons will have a chemical structure of CH3- (CH2)n-2-COOH. Once the fatty acid profile of the oil is known, it is easy to calculate the average molecular weight of the oil. The molecular weight of a single fatty acid ‘i’ can be calculated as:

MWi = 14.027C-2.016d+31.9988

where ‘C’ is the number of carbons and ‘d’ is the number of double bonds. The average molecular weight of fatty acid mixture can be calculated by dividing the sum of all reported fatty acid weights by total moles in the mixture. Numerically,

Average molecular weight of fatty acids = fi / (fi/MWi)

Where, fi are the weight fraction of a reported fatty acid. The molecular weight of the triglyceride (oil molecule) containing three fatty acids can be calculated as:

MW=3*Average molecular weight of fatty acids+38.049

38.049 is the weight of glycerol backbone