Originally Posted by DannoXYZ
That doesn't work because 100% grade is a 45-degree hill. How do you grade hills above 45-degrees?
You are correct that 100% grade is eqaul to a 45 degree hill. Here is the formula:
grade = vertical_climb / horizontal_distance
where both vertical_climb and horizontal_distance are both converted to the same measurement units. So if a hill goes up 264 feet in 2 miles, then we can first convert 2 miles to 10560 feet -- so the grade is then 0.025 = 264 feet / 10560 feet, which is 2.5%
Thus a 45 degree hill is one that for each 1 foot horizontally you travel you go up vertically one foot or
1 ft / 1ft = 1.00 or 100%
Hope that helps everyone.