Example; In the pictures below...
- The model on top is "1:18 Scale", which means it is one eighteenth the size of the real thing.
- The next is "1:24 Scale", so it is one twenty-fourth the real thing and smaller than "1:18 Scale".
- And the last is "1:43 Scale", so it is one forty-third the real thing and smallest of the three.
For a list of all model scales, check out The Wikipedia list of scale model sizes.