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I was wondering if anyone knows what percentage bigger O scale is from HO. I see many HO scale models here I would love to print, but I use O scale and I'm not sure how much bigger percentage wise O is from HO. Or even N scale. I'd love to scale some of these models up and add them to my layout. I'm not too picky, really. Not the kind of model railroader that goes for ultra-realism.

I found a chart on the internet that provides conversion percentages from one scale to another. It says that in order to convert an HO gauge structure to O gauge it should be enlarged to 181% of the original.

Well it is not that simple.
0 Scale is 1:43,5 because half 0 (H0) is 1:87.
On the other hand is 00 1:76 but it uses the same width as H0 Scale, which is not correct, and there is a big community in GB that uses the appropriate width of the track. So it is clearly not about gauges, it is about scale. Spanish models use also the 16,50mm, but they are using iberian wide track.

But there are some oddities to this, whilst in German N-scale is 1:160, Japan uses 1:150.
So it is not only the gauge and scale, it is also the country it is used in.

You Guys Keep Talking about Converting Scales


Wrote this
// Gauges in MM - The is the Distance The Rails Are Apart

F = 45.00; G1 = 45.00;
O = 32.00;
P4 = 18.83; EM = 18.00;
HO = 16.50; OO = 16.50;
N = 9.00; Z = 6.50;

New_Gauge = HO ; Old_Gauge = G1 ; // << Change Here

ReSlide = New_Gauge / Old_Gauge ;

scale(v = [ReSlide, ReSlide, ReSlide]) {

..  .stl                            // << Change Here


Gauge and scale are not fixed to one another. G gauge can be 1:24 or 1:32 (Aristocraft made both as "G") or odd values in that area depending on maker. Sometimes it was due to prototypes being standard or narrow gauge in reality.

KySyth, when changing the size of something, you simply need a percentage to scale by...it does not matter whether you convert scale or gauge. Each scale has a certain gauge....whether you convert scale or gauge, the result is the same....you get a percentage to scale by.
Z is 6.5mm by the way, not 6.
This is a comprehensive explanation of all the different scales....though it may ed up confusing you even more, lol.

Z = is 6.5 , typo

that you said is true , but not if you want it to fit on a track, if you want it to work you must use the gauges, or it a waste of time using scales

a long time ago I Bought an OO Set the Gauge was wrong and did not fit on to my set, end up using it around the christmas tree as I also got the tracks, I have also printer a few coaches converting from G Gauge to HO , the conversion where effective

I will grant you that...IF you are printing rolling stock and IF you are also printing the bogies for them.....however, given the quality that I have seen on here for 3D print trucks and wheels and the fact that the wheels would be plastic, I can't honestly see why you'd want to. I think it would be far better to use commercial trucks with metal wheel sets.
Given that, I stand by my comment that all you need is the percentage, whether you are scaling Scale, or Gauge.

I wish we could add photo, so I can show you some stuff I made, some stuff is just too expensive, easy to made or modify

I got OO HO Peco 100 Tracks , been slowly replacing all the Plastic Wheel with metal ones, add some lead to increase the weight

Built My Own Track Cleaners, used a battery power Train with Lead in them for weight, and used 1.6 volt rechargeable batteries

I model in 1:48 scale in general, to scale down to 1:72 use the scale tool and reduce to 0.67 or 66% I think the same can be applied to O to HO/OO, to scale up from 1:72 to 1:48, multiply by 1.50, 150%. I think n scale is 1:144, so to scale up to O scale multiply by 4, 400% but there is a conversion table on wikipedia. I approximate O scale to 28mm , and 1:48.

I have a Lionel layout I'm working on constantly. Thus the reason why I got into 3d printing to begin with! I'll try 150% and see how that looks, I tried someone else's suggestion here and it seemed to come out way bigger than what I wanted after running a few test prints. Truthfully I'm not to picky about size, ballpark is good. There are some Lionel accessories I have that blatantly are off size wise (look at the figure that's included with the barrel loader!) just as long as it don't look comically off, I'm all good. I guess what I'm trying to say is, I'm not a "rivet counter".

hi friend DrFrankensteam, have anice welcome, so happy that you like the models , i have some mix slaes in my little lay out.. ong time have not time to play with ,, hope you can get the right mesures , calculating the exising ones (aprox) a greeting

Thanks guys for all the help! I'm working on printing a few things I like from HO to O.

Just as an FYI...OO at 1;76, is slightly larger than HO at 1:87....however, they both run on 16mm track, and are considered to be "interchangeable".

Is there actually a name for 1:24?

That's typically referred to as "garden scale" trains, because although those trains are not ride able they are placed outdoors in a garden. It can be anywhere usually between 1:22,5 and larger. I have a few of those myself. However they are not currently set up anywhere on my property. I used to have a extensive run of garden scale trains in my backyard. But it was taken down years ago and put into storage. I mostly do O scale now, or Lionel trains.

Ah thanks for the info, I chose the sizing because it was big enough for printing glassware like wineglasses and small enough to still fit into a smaller project.

HO = 1:87.1 OO = 1:76.2 O = 1:48 to 1:43.5

HO Converted to OO Size x 87.1 / . 76.2 , OO Converted to HO Size / 87.1 x . 76.2

O Converted to OO Size x 48 / . 76.2 ~ O Converted to OO Size x 43.5 / . 76.2 , two possible answers USA and UK Sizes

You Need to Find Out the Gange you are using to print it correctly, Not the Scale

Not always correct. See my earlier reply as to why.

1:48 is the the common size. Or O gauge, basically I model with Lionel trains.

to convert O Gauge to HO/OO Gauge , Size X 16.5 / 32
to convert O Gauge to N Gauge , Size X 9 / 32

I have printer a few Coaches and Used Size X 16.5 / 32 to make HO/OO Gauge from O Scale


Look at the Picture and the width of the track

to convert O Gauge to HO/OO Gauge , Size X 16.5 / 32
to convert O Gauge to N Gauge , Size X 9 / 32

Danke für den Link. Informativ.

O is 1-48 or 1 inch is 48 inches on the model
Hi DrFrankensteam

HO is one half O or 1-87,
N is 1-160
or take a look at this handy page


I hope this helps you