Proper grade & scale

[preceng]

The HO scale is 1:87. Or 1" of model equals 87" of real (prototype), 1 foot of model equals 87 feet .... etc. The grades are generally expressed in percent, which translates scale. A 2% grade is generally a normal, but fairly steep one for real trains. The 2% means the rise divided by the lengths of the slope. For example, a 1" rise in your track for a length of 3 feet (36 inches) would be 1/36 = 0.027, or a 2.7% slope.

[Anonymous]

I'm looking for the proper "grade" I need to give my new HO layout a realistic climb and desent rate..... can anyone help me out on this.
And what is the scale size of Ho to full scale ?