# Model Railroad Scales

Once the available model railroad layout space has been determined, it is time to select the Model Railroad Scale. The Scale is defined as the ratio between the Real World Dimension to the Model Dimension. This ratio for Ho scale is 1/87. Hence 1 foot in the real world is 1/87 of a foot for the model size. If a real world locomotive is 50 feet in length, it would translate to 50ft x 1/87 ft which equals 50/87 ft = 0.57 ft = 6.9 in. for the loco model size.

Basic selection for the scale model to use is based on the following criteria:

N-Scale Model Railroad– With 17 inch minimum diameter, can fit quite a lot of track and model railroad scenery on a 4 x 8 ft table. Backmann trains is one of the top manufacturers of N and HO Scale Model Railroad equipment and supplies

HO-Scale Model Railroads– With 30 inch minimum diameter, can still fit quite a lot of track and model railroad scenery on a 4 x 8 ft table.

O-Scale Model Railroad – With 31 inch minimum diameter, cannot fit a lot of track and model railroad scenery on a 4 x 8 ft table, because the 8 ft sides don’t seem long enough, but train is rugged compared to Ho and N scale. Lionel trains is one of the top manufacturers of O-Scale Model Railroad equipment and supplies.

S-Scale Model Railroad– With 40 inch minimum diameter, cannot fit a lot of track and model railroad scenery on a 4 x 8 ft table, because the 8 ft sides don’t seem long enough and 4 ft sides only have 4 in clearance on each side.

TT-Scale Model Railroad– With 21 inch minimum diameter, can fit quite a lot of track and model railroad scenery on a 4 x 8 ft table.

G-Scale Model Railroad– With a 5 foot minimum diameter, this is definitely the outdoor train model.

For additional information, refer to **Table 1 **for** **a complete** **listing of the more popular Model Scales with each of their attributes. Pay particular attention to the minimum diameter of each scale because it has the biggest impact on layout size. Remember, the sharper the track turns, the more can be put on a model railroad layout table.