HO scale in model railroading is the equivalent of 1:87 scale. This means that the original dimensions are divided by a factor of 87.
HO stands for "half O" scale, a reference to the larger O scale which is 1:48. HO is the most commonly used scale in the realm of model railroading, and it is used for a wide variety of items, making it popular with model railroad enthusiasts. The size allows for a great deal of train activity within a small area. However, the smaller size of the components may make it difficult for smaller children to handle and manipulate.