Nope, in fact it will be smaller. For your case, it's a 3.7x reduction - 3.7cm appears as 1cm on the film plane. If it's 6:1, 6cm will appear as 1cm, that's a smaller image. 1:1 will give you life size reproduction (1cm object = 1cm on the film), 2:1 will give you double life size and so on.