How exactly do you calculate what a grade is?
Also, what kind of a grade would beconsidered realistic? What grades could a person see on an actual railroad?
The most basic formula is units of rise per 100 units of run. I like inches, for simplicity, 8 feet = 96 inches which is pretty close to 100. One inch of rise over that distance, is 1%.
Real railroads work hard to keep their grades under 2%. Though they can climb steeper grades, it costs more money, and avoid doing it whenever they can. Half the load or double the power, per 1% grade increase, is a quick rule.
Models can get away with a little steeper grade, 4% maybe, but the lower you can keep it the better off you are.
I like it metric!
1m = 100 cm so if you’re grade is 3% this will mean a rise of 3cm for every meter.
BTW as far as I know they sell measuring tapes that are metric and inch in the USA.
If you like good operation running mainline keep your grades at 2% max.