Your rack will store one bottle per module plus the extra bottles you can store across the top of the rack. Each module requires 10.5cm of rack height and 10.5cm of width. Your rack width then will be the number of modules multiplied by 10.5 cm and your rack height will be the number of modules multiplied by 10.5 cm.
Print out our module estimating sheet to help you work out how many modules can be fitted into an irregular space or under a sloping ceiling or staircase