In participatory too many projects generates choice overload.•
An utilitarian or a Rawlsian approach can be adopted in selecting projects.•
The costs and benifits of projects should be included in the voting stage.
In participatory budgeting, citizens are invited to vote on different projects. This paper sets out to study the voting stage of participatory budgeting from theoretical and practical perspectives. At theoretical level, the potential objectives of voting procedures are examined. From the practical point of view it should be easy to select projects, even when the number of projects is large. This paper proposes three algorithms which are theoretically justified and can be easily applied. Participatory budgeting in the town of Portugalete (Spain) provides a test for them. The results obtained with 2018 voting data suggest that the algorithm that includes the costs of the projects at the selection stage performs better than the others. KEYWORDS: decision processes; participatory budgeting; collective decision-making; cost-benefit analysis.