Incline Conveyor Calculators When planning for a conveyor system design, there are numerous factors that need to be taken into account. These calculators are designed to assist in working out safe incline angles, conveyor heights, and other useful measurements. The box tumbling calculator gives the maximum angle at which products can safely be transported without tumbling. Please note: These should be used as a guide only. When constructing a conveyor system please seek advice from a specialist.