What is the scale of HO trains?

[Anonymous]

I am building an HO scale train layout and I want to reproduce my house, but I don't know the exact scale of HO. It's a one for what scale? And how tall is a real train (in feet)?

[tomwatkins]

HO is 1/87th actual size. The height of a locomotive or rolling stock will vary depending on type.

[BNSFNUT]

The best way I found to build any thing in HO scale is with an ruler marked in HO feet and inches. Just take the prototype dimention and musure your material with the scale rule.
Your hobby shop can get you the ruler that you need. I have one made of metal that I have used for about 20 yrs.

[Anonymous]

3.5 milimeters equals one prototype foot (12-in).

[dknelson]

the metal scale ruler is very good and I strongly advice having one
There is also a clear flexible plastic scale ruler that is helpful.
Sometimes you will hear people say that 1/8" to the foot is "good enough." It would not be anywhere good enough for cars or locomotives or track but it might be a decent rule of thumb for trees, hills, river, and maybe very large buildings, so long as the doors were built to accurate scale (otherwise it would be like Alice in Wonderland trying to fit in the shrinking door)
David Nelson