1 in (1 .052408) = Roof Pitch: Slope Percentage: We call the change in the values of y "rise", since it is along the vertical axis. Rate this calculator and tell us what you think about it and if it can be improved in any way. Multiply c by x and add this to the new line. Slope - Degree, Gradient and Grade Calculator. A line perpendicular to your original line has a slope of 1/4. The third row shows the calculation of the true horizontal run which is 15840 feet. Roofs can be steeper than shown in the table above. Put those values in the point slope format to get an equation of that line in point slope form: If you simplify the point slope equation above you get the equation of the line in slope intercept form. Calculate Your Incline Conversion Chart = Change measurement units / ratio Rise in CM / IN / FT / M Ratio ratio 1:6 / 1:8 / 1:10 (IRC) / 1:12 (ADA) Slope deg Grade % Run Length ft CM / IN / FT / M If you'd like to know how to build a ramp that complies with ADA ramp requirements, we have included the tips. If you have the equation for a line you can put it into slope intercept form. angle A = arctangent (rise run) which equals With the deck stain calculator, you can easily estimate the volume of stain that you need to cover your deck.