Knowing a board's lineal metre factor (LMF), you can calculate the lineal metres of boards needed to cover an area. It is based on that part of the board (exposed face) that adds to the coverage of the wall area. Cladding you usually install with an amount of overlap. You have to subtract the amount of overlap from the width of the board to get the exposed face amount, and for a horizontal install, divide the height of the wall by this exposed face amount to get the number of rows needed to cover the wall. Multiply this by the length of the wall, and you have the lineal metre amount of boards needed.
The lineal metre factor provides you with a shortcut, and it quickly calculates the lineal metre amount of boards needed to cover a wall measured in square metres.
The actual width of the board is 235 mm and is installed with a 50 mm overlap, giving it an exposed face value of 235 - 50 = 185 mm. The length of the wall is 4.6 metres The wall height is 2.4metres
Enter 185 in the calculator to get the lineal metre factor;
The result, 5.40541
The lineal metre factor for the board with an exposed face of 185 mm is 5.40541.
Calculate the square metres of the wall;
4.6 * 2.4 = 11.04
The wall has an area of 11.04 square metres.
Multiply the area of the wall by the lineal metre factor;
11.04 * 5.40541 = 59.67572 rounded to 60
You need 60 lineal metres of this type of board.