Ramp Calculator

Designing a reliable ramp relies on fundamental trigonometry and algebraic ratios. The core relationship connects the vertical height you need to overcome—known as the rise—with the horizontal ground distance it covers, called the run. The primary formula utilized is the rise-to-run ratio: rise / run = tan(slope_angle). To find the exact length of the inclined path you must build, the calculator determines the hypotenuse using the cosine of the slope angle, formulated as ramp_length = run / cos(slope_angle). Furthermore, elevation grade is expressed as a percentage, calculated directly by dividing the rise by the run and multiplying by 100.

Imagine you need to construct a wheelchair access ramp leading to a doorway with a total vertical rise of 30 inches. According to standard accessibility guidelines for a safe incline, you choose a standard 1:12 rise-to-run ratio. First, calculate the horizontal run by multiplying the rise by 12, which gives us 30 inches × 12 = 360 inches (or 30 feet) of horizontal ground space. Next, find the slope angle using the inverse tangent of the grade (1/12 or 0.0833), resulting in an angle of approximately 4.76 degrees. Finally, compute the actual physical ramp_length (the hypotenuse) by dividing the run by the cosine of 4.76 degrees, yielding approximately 361.2 inches. This ensures your materials order accounts for the exact inclined board length required.

Always verify local building codes before breaking ground, as municipal regulations can sometimes be stricter than general federal guidelines. For public accessibility, never exceed a 1:12 slope ratio to prevent rollaways and excessive physical exertion. Always incorporate level resting landings at least every 30 feet of horizontal run, as well as at the top and bottom of any inclined path, to provide users a safe space to pause.