Finding the scale of a model?

I built a model of the St.louis arch. I need to figure out the scale my model is 5 inches tall and the arch is 630 ft tall. I think I need to do 630ft/5in x x/100 and I get 126ft per inch. is that right?Finding the scale of a model?
Here's a handy program(safe download) to figure out any scale, model, etc.:



http://www.starshipmodeler.com/tech/scal鈥?/a>
The scale is 1512:1. Convert the feet to inches (630 x 12) and divide by 5. You want to get the actual item and your model in the same units (inches).Finding the scale of a model?
yes, but



Its really a 1 to 1514 scale