Despite several scientific research investigations on hydrothermal liquefaction of microalgae, there is limited study on predictive models. In this paper a model predicting biocrude yield for hydrothermal liquefaction of microalgae was developed, allowing interaction of carbohydrates, lipids and proteins. The results showed that the developed model could predict biocrude yield from experimental HTL of Nannochloropsis sp., Spirulina sp. and Tetraselmis sp., accounting for differences in biochemical composition. The model corroborates with HTL experimental data; that algae high in lipids and proteins leads to higher biocrude yield than microalgae high in carbohydrates.