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.  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) Introduced by; Manufactured by
Z 1:220 116” = 1’ 6.5mm Marklin 1972; Micro-Trains
N 1:160 316” = 1’ 9mm Arnold 1962; Peco; Fleischmann
TT 1:120 110” = 1’ 12mm H.P. Products 1945; Tri-ang; Tillig
HO 1:87 ⅛” = 1’ 16.5mm American Flyer; Lionel; Walthers
On30 1:48 ¼” = 1’ 16.5mm Bachmann; Accucraft
OO (European) 1:76.2 4mm=1’ 16.5mm Bing 1921; Marklin; Trix
OO (Lionel) 1:76 532” = 1’ ¾” Lionel 1938
S 1:64 316” = 1’ ⅞” American Flyer; MTH
O 1:48  ¼” = 1’ 1¼” Marklin circa 1900
1 1:30 or 1:32  ⅜” = 1’ 1¾” Marklin 1891; Elektoy; Bing; Carette
G 1:22.5 – 1:32 ½” = 1’ 1¾” LGB 1968; Bachmann; Lionel
2 1:22.5 – 1:28 ½” = 1’ 2” Marklin 1891; Carlisle & Finch; Voltamp
Standard (Lionel) 1:24  ½”= 1’ 2⅛” Lionel 1906; American Flyer
3 1:16 – 1:23 ¾” = 1’ 2½” Marklin 1891; Bing; Carette; Schonner
4 1:11 or 1:20 1” = 1’ 2⅞” Marklin 1891; Bing; Lionel 1901
5 1:8 4” = 1’ 4.72” Marklin 1891
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 2⅝ or 2½”
G 3½”
2 3½ – 2⅞”
Standard (Lionel) 3⅜”
3 5” – 3½
4 7¼ or 4”
5 10”