Plans in model railroad books and magazines are often in a different scale from your favorite. Having a model railroad scale conversion chart helps.
I’m into O scale and the rest of the world, it usually seems, is not. Dimensions for published plans are almost always sized to HO scale, or even S scale of all things. Of course, after A. C. Gilbert imploded in 1967 and took American Flyer with it, it seemed like the “S” is S scale stood for “scratchbuild,” because building it yourself was the only way you were going to get anything, so I guess that’s fair.
Here’s a cheatsheet you can use to convert measurements from one scale to another.
Assumptions: O scale is 1:48, G scale is 1:22.5. If you use a different measurement for either scale, I’m sorry. This won’t be much use to you.
| G Scale|| O Scale||S Scale||OO Scale||HO Scale||TT Scale||N Scale||Z Scale|
Find your scale in the table along the top. Then scroll down to the desired scale and find out the factor you need to enlarge or reduce. So, if, say, I have HO scale plans I want to enlarge to O scale, I run across the top to HO, then down to O scale, and see that I need to enlarge the plans to 181%. If I have O scale plans I want to reduce to S scale, I run across the top to O and down to S, and see I need to reduce the plans to 75%.
You can also do this if a building you want exists in kit form for a different scale. Measure it. Then do the math based on the chart to figure out what size to build everything for your scale of choice.
I hope you find this model railroad scale conversion chart useful.
On a somewhat related note, if you’re unsure what scale something is, here’s how to figure that out before you convert it. You might also find my cross-hobby scale conversion helpful.