Toy Train Scales & Gauges

Below is a table of approximate scales and gauges for many toy trains over the past century or so.  “Approximate” because unlike “model train” scales (many of which have actual standards set by the NMRA), toys were… well… toys.  Toy train makers often made no attempt to ‘scale’ their wares to actual prototypes.  Moreover, various manufacturers interpreted the various scales and gauges differently. Some measured gauge between the inside of the outer rails - others measured gauge between the center of the outside rails. For instance, vintage Carette Gauge-1 engines won’t run on modern Marklin Gauge-1 track. 

So consider this a VERY rough rule-of-thumb…

Toy Train Scales/Gauges

Desig­nation Ratio Approx. Scale Gauge (Between Outer Rails) Manufacturers (Introduced by; Notable Firms)
Z 1:220 116” = 1’ 6.5 mm Marklin 1972; Micro-Trains
N 1:160 316” = 1’ 9 mm Arnold 1962; Peco, Fleischmann
TT 1:120 110” = 1’ 12 mm H.P. Products 1945; Tri-ang, Tillig
HO 1:87 ⅛” = 1’ 16.5 mm Bing 1922; Hornby, Lionel, Walthers
On30 1:48 ¼” = 1’ 16.5 mm Bachmann; Accucraft
OO (European) 1:76.2 4mm = 1’ 16.5 mm Bing 1921; Marklin, Trix
OO (Lionel) 1:76 532” = 1’ ¾” Lionel 1938
S 1:64 316” = 1’ ⅞” American Flyer; Lionel, MTH, American Models
O 1:48  ¼” = 1’ 1¼” (32 mm)* Marklin ~1900, Carette, Bing, Lionel, Ives, AF, Marx, MTH
1 1:32  ⅜” = 1’ 1.75” (45 mm)* Marklin 1891; Bassett-Lowke, Elektoy, Bing, Carette, Ives
G 1:22.5 ½” = 1’ 1.75” (45 mm ) LGB 1968; Bachmann, Lionel
2 1:22.5 – 1:28 ½” = 1’ 2” (51mm)* Marklin 1891; Carlisle & Finch, Voltamp, Bassett-Lowke
Standard (Lionel) 1:24  ½”= 1’ 2⅛” Lionel 1906; American Flyer, Ives, Boucher, McCoy
3 1:16 – 1:23 ¾” = 1’ 64 mm* Marklin 1891; Bing, Carette, Schonner
2⅞"     2⅞" Lionel 1901, McCoy, JLM Trains
4 1:11 – 1:20 1” = 1’ 72 mm* Marklin 1891; Bing
5 1:8 4” = 1’ 117 mm* Marklin 1891

* When Marklin introduced gauges 0-5, they measured gauge as the distance between the centers of the outside rails. This is approximately
3 mm wider than the modern definition of gauge as distance between the outside rails. The early Marklin specs for gauges 0-5 were 35mm,
45mm, 54mm, 67mm 75mm & 120mm respectively. Gauges 1 & 2 seem to have standardized at the imperial measurements of 1.75" and 2"
early in the 20th century.

For comparison here are (very) approximate standard door heights for each scale/gauge – based on an 80” door – to the nearest ⅛”.

Designation Door Height
Z ⅜”
N ½”
TT ⅝”
HO ⅞”
On30 1⅝”
OO (European) 1”
OO (Lionel) 1”
S 1¼”
O 1⅝”
1 2½ – 2⅝”
G 3½”
2 2⅞ – 3½”
Standard (Lionel) 3⅜”
3 3½ – 5”
4 4 – 7¼ ”
5 10”