These are conversion charts I use as part of my scale model workflow. When I create my furniture pieces, I often design directly in scale. To do so, I need to translate real world measurements into scale and into mm. I keep these charts handy to make things easier. I also put together a scale ruler for each, that shows inches, mm and scale feet for the given scale all on one page.
Check out my post on the subject on MakerBot's blog: http://www.makerbot.com/blog/2012/05/04/makerbot-miniatures-developing-a-workflow/
Conversion Charts available:
The charts follow this basic equation:
((Feet12) +Inches) (scale factor) * (metric conversion factor) = dimension in scale, in mm
Make sure to print these files at 100% - do not "scale to fit page". Double check the printed rulers before using.
For a limited time, I'll take requests to add more scales to the list if folks are interested. Enjoy!