Diagonal Plate Length

Use this Diagonal Plate Length Calculator to determine the exact diagonal length of a plate based on the given slope ratio and bottom plate length in feet and inches. This tool is ideal for construction projects requiring precise measurements. Enter the slope ratio, the bottom plate length in feet (positive integer), and the size in inches (including mixed numbers). Specify the desired fraction precision and click "Calculate" to get the result in feet and inches, formatted as 12' 8 3/4". This calculator helps you ensure accuracy and efficiency in your construction projects.

Gable Wall Top Plate Length

Diagonal Plate Length Calculator

Calculation

the slope ratio (the amount of rise in 12 inches of run)
the length of the bottom plate in feet and or inches (feet has to be an integer e.g. 12 the inches can be a mixed number e.g. 3 5/16, a space between the integer and fraction parts)
the denominator of the fraction used in the result (preset @ 16)

Results

length of the diagonal plate in inches
the length of the diagonal plate in feet and inches (12' 8 3/4")

Example calculation:

5: 12 slope ratio
bottom plate length = 15' - 5" = 185 inches
Calculate the slope factor from the slope ratio;
To be able to do this, you need to know the formula that converts the slope ratio to a slope factor.
Slope Factor Formula = √rise*rise+run*run/12

Plug in the values: √5*5+12*12/12 = 1.083333333.
Multiply the bottom plate length by the slope factor to get the diagonal plate length;
185 *1.083333333 = 200.4166667 = 200 7/16 inches.
The diagonal plate length is 200 7/16 inches or 16' - 8 7/16"

Diagonal Plate Length