An algorithm for calculating the strength and reliability of centrifugal fire pump housings has been developed, aimed at determining the optimal mass-dimension parameters of centrifugal fire pumps. To this end, a method has been devised for determining the main indicators of reliability, an optimization mathematical model has been built, and an algorithm for solving the optimization problem using the Monte Carlo method has been developed. When devising a method for determining the main reliability indicators of centrifugal fire pumps, the strength and kinematic parameters have been taken into consideration, as well as an economic indicator of reliability and the costs of ensuring reliability. These indicators make it possible to establish the optimal consumption of materials for the manufacture of structural elements of centrifugal fire pumps that ensure their strength and reliability. When building the optimization mathematical model, a pump weight minimization was used as the objective function while the applied difference criterion makes it possible to take into consideration the economic indicator in the manufacture of centrifugal fire pumps and to reduce their cost. It was established that the principal indicator that affects the weight of a pump and the cost of its manufacture is the thickness of the pump housing wall. Based on the developed optimization mathematical model, the flowcharts of the algorithms have been constructed for solving it using the Monte Carlo method. The calculation results showed that the width of the PN-40 UV pump housing can be reduced by 1.18 from the rated one. Applying the optimization mathematical model in the process of designing fire centrifugal pumps makes it possible to reduce the pump weight by 9‒11 % while ensuring high reliability and reducing the cost of its production by 10 %