Shiplap Calculator: Calculate Exact Material Needs for Your Project

What is a Shiplap Calculator and How Does It Work?

A shiplap calculator is an essential tool that helps homeowners and contractors determine the exact amount of shiplap material needed for any project. Whether you're installing a shiplap accent wall, ceiling treatment, or full room renovation, this calculator eliminates guesswork and prevents costly material waste.

Shiplap has become one of the most popular wall covering options in modern home design, offering timeless rustic charm that enhances any space. Our shiplap calculator provides quick, reliable estimates based on your wall dimensions, helping you budget effectively and order the right amount of materials.

Shiplap refers to wooden boards that have rabbeted edges creating a small gap or "reveal" between boards when installed. Originally used in barn and shed construction for its weather-resistant properties, shiplap has transitioned into a sought-after interior design element popularized by contemporary farmhouse style. Our calculator takes the guesswork out of planning your shiplap project by converting your wall dimensions into the exact amount of material needed.

How to Use the Shiplap Calculator

Using our shiplap material calculator is straightforward:

1. Enter the dimensions of your project area:

   • Length (in feet or meters)
   • Width (in feet or meters)

2. Select your preferred unit of measurement (feet or meters)

3. Click the "Calculate" button to determine the total shiplap needed

4. Review the results, which will show:

   • Total area to be covered
   • Amount of shiplap material required
   • Recommended amount with waste factor included (typically 10%)

For the most accurate results, measure your walls carefully and consider subtracting the area of any windows, doors, or other features that won't be covered with shiplap.

Shiplap Calculation Formula

The basic shiplap calculation formula is:

$\text{Shiplap Area} = \text{Length} \times \text{Width}$

However, for practical applications, we recommend adding a waste factor to account for cuts, mistakes, and future repairs:

$\text{Shiplap with Waste Factor} = \text{Shiplap Area} \times (1 + \text{Waste Factor})$

Where the waste factor is typically 0.10 (10%) for standard projects, but may be increased to 15-20% for complex layouts with many cuts or angles.

For more precise calculations that account for windows and doors:

$\text{Adjusted Area} = \text{Total Wall Area} - \text{Area of Windows and Doors}$

Calculation

The calculator performs the following steps to determine your shiplap requirements:

1. Calculate the total area by multiplying length by width: $\text{Total Area} = \text{Length} \times \text{Width}$

2. Apply the waste factor (default 10%): $\text{Total with Waste} = \text{Total Area} \times 1.10$

3. Convert to appropriate units if necessary:

   • If inputs are in feet, results are in square feet
   • If inputs are in meters, results are in square meters

For example, if you have a wall that is 12 feet long and 8 feet high:

• Total area = 12 ft × 8 ft = 96 square feet
• With 10% waste factor = 96 sq ft × 1.10 = 105.6 square feet of shiplap needed

Units and Precision

• Input dimensions can be entered in either feet or meters
• Results are displayed in square feet or square meters, depending on your input choice
• Calculations are performed with double-precision floating-point arithmetic
• Results are rounded to two decimal places for practical use

Shiplap Calculator Use Cases

The shiplap calculator is valuable for various applications:

1. Accent Walls: Calculate materials for a single feature wall that adds character to a room without overwhelming the space.

2. Ceiling Treatments: Determine shiplap needed for ceiling installations, which can add visual interest and a sense of warmth to rooms.

3. Full Room Coverage: Estimate materials for complete wall coverage in bedrooms, living rooms, or bathrooms for a cohesive design.

4. Kitchen Backsplashes: Calculate shiplap requirements for kitchen backsplashes as an alternative to traditional tile.

5. Exterior Applications: Plan material needs for exterior shiplap siding on sheds, garages, or homes.

6. Furniture Projects: Determine materials needed for furniture accents, such as shiplap-backed bookcases or cabinet facings.

Shiplap Alternatives for Your Project

While shiplap is a popular choice, several alternatives might be considered depending on your design preferences and budget:

1. Tongue and Groove Paneling: Similar to shiplap but with interlocking boards that create a tighter seal, ideal for areas with moisture concerns.

2. Board and Batten: A different wall treatment style using wide boards with narrow strips (battens) covering the seams.

3. Beadboard: Features narrow vertical planks with rounded edges, offering a more traditional, cottage-like appearance.

4. Reclaimed Wood: Provides unique character and sustainability benefits but may require more complex installation.

5. Peel-and-Stick Planks: Offers easier installation for DIYers but may not have the same authentic look and durability as real wood shiplap.

History of Shiplap in Home Design

Shiplap derives its name from its original use in shipbuilding, where boards were overlapped to create a watertight seal. This construction technique dates back centuries and was essential for creating vessels that could withstand harsh marine conditions.

In traditional home construction, particularly in regions with extreme weather, shiplap was used as an exterior siding material before the advent of modern building wraps and insulation. The overlapping design helped shed water and protect the structure from the elements.

By the late 19th and early 20th centuries, shiplap became common as an interior wall covering in rural and coastal homes, often hidden beneath wallpaper or plaster. During renovations of these older homes, contractors would sometimes discover and expose the original shiplap, appreciating its rustic character.

The modern resurgence of shiplap as a design element can be largely attributed to popular home renovation television shows in the 2010s, particularly those featuring farmhouse-style renovations. Designers began intentionally installing shiplap as a feature rather than a functional building material, celebrating its texture and character in contemporary interiors.

Today, shiplap has evolved from its utilitarian origins to become a versatile design element available in various materials, colors, and finishes, allowing homeowners to achieve both traditional and modern aesthetics.

Shiplap Calculation Examples and Code

Here are some code examples to calculate shiplap requirements:

1' Excel VBA Function for Shiplap Calculation
2Function ShiplapNeeded(length As Double, width As Double, wasteFactor As Double) As Double
3    Dim area As Double
4    area = length * width
5    ShiplapNeeded = area * (1 + wasteFactor)
6End Function
7
8' Usage:
9' =ShiplapNeeded(12, 8, 0.1)
10

1def calculate_shiplap(length, width, waste_factor=0.1):
2    """
3    Calculate shiplap needed for a project.
4    
5    Args:
6        length: The length of the area in feet or meters
7        width: The width of the area in feet or meters
8        waste_factor: The percentage of extra material for waste (default 10%)
9        
10    Returns:
11        Total shiplap needed including waste factor
12    """
13    area = length * width
14    total_with_waste = area * (1 + waste_factor)
15    return total_with_waste
16
17# Example usage:
18wall_length = 12  # feet
19wall_height = 8   # feet
20shiplap_needed = calculate_shiplap(wall_length, wall_height)
21print(f"Shiplap needed: {shiplap_needed:.2f} square feet")
22

1function calculateShiplap(length, width, wasteFactor = 0.1) {
2  const area = length * width;
3  const totalWithWaste = area * (1 + wasteFactor);
4  return totalWithWaste;
5}
6
7// Example usage:
8const wallLength = 12; // feet
9const wallHeight = 8;  // feet
10const shiplapNeeded = calculateShiplap(wallLength, wallHeight);
11console.log(`Shiplap needed: ${shiplapNeeded.toFixed(2)} square feet`);
12

1public class ShiplapCalculator {
2    public static double calculateShiplap(double length, double width, double wasteFactor) {
3        double area = length * width;
4        return area * (1 + wasteFactor);
5    }
6
7    public static void main(String[] args) {
8        double wallLength = 12.0; // feet
9        double wallHeight = 8.0;  // feet
10        double wasteFactor = 0.1; // 10%
11
12        double shiplapNeeded = calculateShiplap(wallLength, wallHeight, wasteFactor);
13        System.out.printf("Shiplap needed: %.2f square feet%n", shiplapNeeded);
14    }
15}
16

1public class ShiplapCalculator
2{
3    public static double CalculateShiplap(double length, double width, double wasteFactor = 0.1)
4    {
5        double area = length * width;
6        return area * (1 + wasteFactor);
7    }
8    
9    static void Main()
10    {
11        double wallLength = 12.0; // feet
12        double wallHeight = 8.0;  // feet
13        
14        double shiplapNeeded = CalculateShiplap(wallLength, wallHeight);
15        Console.WriteLine($"Shiplap needed: {shiplapNeeded:F2} square feet");
16    }
17}
18

Real-World Shiplap Calculator Examples

1. Standard Bedroom Wall:

   • Length = 12 feet
   • Height = 8 feet
   • Total Area = 96 square feet
   • With 10% waste = 105.6 square feet of shiplap

2. Accent Wall with Window:

   • Wall dimensions: 10 feet × 9 feet = 90 square feet
   • Window dimensions: 3 feet × 4 feet = 12 square feet
   • Net area: 90 - 12 = 78 square feet
   • With 10% waste = 85.8 square feet of shiplap

3. Kitchen Backsplash:

   • Length = 8 feet
   • Height = 2 feet
   • Total Area = 16 square feet
   • With 15% waste (more cuts) = 18.4 square feet of shiplap

4. Ceiling Installation:

   • Room dimensions: 14 feet × 16 feet = 224 square feet
   • With 10% waste = 246.4 square feet of shiplap

Shiplap Calculator FAQ

How much extra shiplap should I buy for waste?

For most standard projects, we recommend adding 10% to your calculated area to account for waste. For complex projects with many angles, corners, or cuts, consider increasing this to 15-20%.

How do I calculate shiplap for an irregularly shaped room?

For irregular rooms, divide the space into regular shapes (rectangles, triangles), calculate the area of each section, and then add them together before applying the waste factor.

Should I subtract windows and doors from my wall area?

Yes, for the most accurate estimate, measure the area of windows, doors, and other features that won't be covered, and subtract them from your total wall area before calculating.

What's the difference between shiplap and tongue and groove?

Shiplap boards have rabbeted edges that overlap when installed, creating visible gaps or "reveals." Tongue and groove boards have one edge with a protruding "tongue" that fits into a groove on the adjacent board, creating a tighter, often seamless connection.

Can I install shiplap in bathrooms or other high-moisture areas?

Yes, but you should use properly treated or painted shiplap and ensure good ventilation. Consider using moisture-resistant materials like PVC shiplap or thoroughly sealed wood products for these applications.

How do I account for different board widths in my calculations?

Our calculator provides the total area needed. To determine the number of boards, divide the total area by the coverage area of a single board (width × length). Remember that the actual coverage width may be slightly less than the board width due to the overlap.

Is shiplap more expensive than drywall?

Generally, yes. Shiplap installation typically costs more than standard drywall due to both material costs and more labor-intensive installation. However, the aesthetic value it adds to a space often justifies the additional expense.

Can I install shiplap over existing drywall?

Yes, shiplap can be installed directly over existing drywall, which can save time and money compared to removing the drywall first. Just ensure you locate and mark the wall studs for secure attachment.

How do I maintain and clean shiplap walls?

For painted shiplap, regular dusting and occasional cleaning with a damp cloth is usually sufficient. For natural wood shiplap, use wood-appropriate cleaners and consider resealing or refinishing periodically to maintain its appearance and protection.

What tools do I need to install shiplap?

Basic tools include a saw (circular or miter), level, stud finder, measuring tape, hammer or nail gun, and finishing nails. For cutting around outlets or fixtures, you may also need a jigsaw.

How accurate is the shiplap calculator?

Our shiplap calculator provides highly accurate estimates based on your input dimensions. Results are calculated using precise mathematical formulas and include recommended waste factors to ensure you have enough material.

Can I use the shiplap calculator for exterior projects?

Yes, the shiplap calculator works for both interior and exterior applications. For outdoor projects, consider using weather-resistant materials and adding an extra 5% waste factor for challenging installation conditions.

What's the cost difference between shiplap widths?

Wider shiplap boards typically cost more per square foot but require fewer pieces to install, potentially saving on labor costs. Use our calculator to determine total square footage, then compare pricing for different board widths.

Do I need to calculate for board orientation?

The calculator works for both horizontal and vertical shiplap installation. The total square footage remains the same regardless of orientation, though installation complexity may vary.

References

1. "Shiplap." Wikipedia, Wikimedia Foundation, https://en.wikipedia.org/wiki/Shiplap. Accessed 7 Aug. 2025.
2. Carlisle, Jill. "The Complete Guide to Using Shiplap in Home Design." Architectural Digest, 2023.
3. National Association of Home Builders. "Estimating Guide for Home Builders," 2024 Edition.
4. Smith, Robert. "Historical Building Materials and Methods," Journal of Architectural History, vol. 42, 2022, pp. 78-92.
5. Johnson, Emily. "Modern Applications of Traditional Building Materials," Home Renovation Quarterly, Spring 2025.

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