Foamed concrete is a type of lightweight concrete, more than 20% of its volume is air. It possesses high flowability, thermal and acoustic insulation, and low dead load (less aggregate). Due to the philosophy of foam concrete, designing and obtaining the desired densities require a lot of trial mixes and time. Therefore, the main objective of this research is to predict mix proportions and mechanical performance of foamed concrete. Materials used include cement, sand, water and foaming agent (NEOPOR Brand) of organic origin. Fifteen different densities (among 300–1000 kg/m3) were targeted. In the present research density, compressive strength, splitting tensile strength and ultrasonic pulse velocity tests were performed. The results demonstrated that there is a reliable positive relationship between density and strength of foamed concrete. The ultrasound pulse velocity (UPV) test is closely related to the density and mechanical performance of foamed concrete, and thus based on the UPV test, mathematical models were used to determine the mix proportions and strength. Models were validated using data of current and other research works. A high determination coefficient (R2 > 0.8) was achieved for all validations, supporting reliability and the use of these models in future research.