Welcome to the forum, and good tips from Flexibull. You'll find that most, if not all copiers, work to a different system for enlargement reproduction, and it's a real pain in the nether regions! I'm used to working with graphic - reproduction process cameras, where enlargement and reduction is logical, for example, 1/48th scale up to 1/32nd scale is = 150% enlargement - simple!
Copiers however use a ratio for the paper or copier bed size, so a calcualtion has to be made to achieve a nearly correct enlargement size to input, which will still not be accurate! Copier operators, for instance at 'Copy Shops' and similar establishments, will know how to do this, but I haven't a clue!