Hello can some one tell me the differant scales of the model trains.
Thanks Tender1

From smallest to largest

Z - 1:220
N - 1:160
HO - 1:87
S - 1:64
O - 1:48
G - 1:32, 1:29, 1:24, 1:22.5, 1:20.3, plus a few others

A few additional scales here:

http://en.wikipedia.org/wiki/Model_train_scales

Also
TT 1:120
T scale 1:450
ZZ scale 1:300

Heres a little more info on the primary scales
http://www.walthers.com/exec/page/set_scales#zscale

A BIG THANK YOU TO ALL FOR YOUR INFO.
TENDER1

There is also 5.5mm/ft or 1/55 scale which has no letter but has been around since 1963.

I like to think the guys in the proto rail versions of the scale have a better system: Proto:87, Proto:64, Proto:48, than the letters. Internationally there are other versions of the "letter" scales using a different ratio which creates confusion.

So 1/55 is Scale 55.

Harold

There is also OO scale, which is 1:76 or 4mm = 1 foot.  This is the most popular scale in the UK.  The trains actually run on HO gauge track, which is prototypically too narrow.  You will sometimes run across models in the US that are noted as being HO/OO scale.  These are in fact normally OO scale models.  Note that the Bachmann Thomas series and the Harry Potter trains are OO scale, but run on HO track.