Model Train Scale Size in Inches and MM

For creating model railroading train models and accesories, this calculator will tell you how big something needs to be in the scale of your choice compared to the real world size. For instance, if you want to know the size of a door in "N" Scale, enter the amount of inches a door would be (like about 84 for a 7 foot door).  

Make sure Input Scale is set to Real World if you are converting Real World sizes to a scale size. Set the Output Scale to your choice (N Scale, HO Scale, etc.).  Then click the Convert button for the answer. Answer is shown at bottom in Inches and Millimeters)

You can also convert from one scale to another. Example,.. you can convert HO to N scale by entering the HO size in inches (say like 3 inches), select HO for the input and select N scale for the output then click the Convert button. You now have the size that it would be in N Scale at the bottom.