Märklin introduced the Z Gauge (1:220 scale) in 1972. It is the smallest currently-available model railway scale.

Although its very small size can be used to make proportionally small layouts, its proponents cite its primary advantage as being able to produce more scale miles in the same space that would be used by a larger-scale layout. For example, a 4x8 sheet of plywood is 384 scale feet long in O scale. The same space is 1760 feet—1/3 of a mile—in Z scale. Even when compared to N scale, Z scale permits 37.5% more mileage in the same space.

This allows longer trains and smoother curves, and thus more realistic operation than is possible in larger scales under most circumstances.

There are now many different manufacturers of this equipment, and it has thus become less of a curiosity and more of a legitimate modelling scale. However, Z-scale rolling stock, buildings and figures remain much more scarce than their counterparts in the two most popular scales, HO and N.