Enter the total square footage of the wall and select the size of the shiplap to determine the total number of shiplap needed.

## Shiplap Formula

The following formula is used to calculate the total number of shiplap needed to fill a wall.

SL = TA / SLA
• Where SL is the number of shiplaps
• TA is the total area of the wall (ft^2)
• SLA is the total area of the shiplap (ft^2)

For the equation above, a person should always round up by at least 1 to have extra coverage if needed.

To calculate the number of shiplaps needed, divide the total area of the wall by the total shiplap area.

## Shiplap Definition

What is a shiplap?

A shiplap is a ground of boards that are used for covering walls and roughs that are most often used for cladding.

## Example Problem

How to calculate the number of shiplaps?

First, determine the total area that needed to be covered. In this example, we are looking at a wall that has a total area of 200 square feet of space.

Next, determine the area of one shiplap. The ship laps this person wants to use are a total of 7″ X 16″. To calculate the area of this shiplap, we multiply the length and width and then divide by 144 to get the result in square feet.

SLA = L*W/144

SLA = 7*16/144 = .777 ft^2

Finally, calculate the total number of shiplaps needed for this projected using the formula above:

#SL = 200 / .777

#SL = 257.58

You should then round up to at least 258 boards.