Linear Feet Decking Calculator
Accurately estimate the total amount of decking material needed for your project. Enter your deck’s dimensions to get an instant calculation of the required linear feet.
Enter the total width of the area you need to cover.
Enter the length of your deck boards (the direction they will run).
Enter the actual width of a single deck board (e.g., 5.5 for a “6-inch” board).
Common gaps are 1/8″ (0.125) or 1/4″ (0.25).
Total Linear Feet Needed
448.00 ft
Total Deck Area
Total Boards Needed
Effective Board Width
| Waste Factor | Additional Linear Feet | Total Recommended Linear Feet | Common Use Case |
|---|
What is a Linear Feet Decking Calculator?
A linear feet decking calculator is a specialized tool designed to determine the total length of deck boards required to cover a specific area. Unlike a simple area calculator, it accounts for the actual width of the individual boards and the necessary gap between them. This calculation is crucial for homeowners and contractors to purchase the correct amount of material, preventing shortages or excessive over-buys. The final result is given in “linear feet,” which is simply a measure of total length, irrespective of width.
This tool is essential for anyone planning a decking project. By inputting the dimensions of your deck and the materials you’re using, you get a precise number for your shopping list. Using a linear feet decking calculator saves time, reduces waste, and helps budget your project more accurately. You might also find our decking material cost estimator useful for budgeting.
Linear Feet Decking Formula and Explanation
The calculation is a two-step process. First, we determine how many boards are needed to span the width of the deck. Second, we multiply that number by the length of each board to find the total linear footage.
The core formula is:
Total Linear Feet = (⌈Deck Width / (Board Width + Gap Width)⌉) * Deck Length
Note: All units must be consistent. If your deck dimensions are in feet, you must convert the board and gap widths from inches to feet before calculating.
| Variable | Meaning | Unit (auto-inferred) | Typical Range |
|---|---|---|---|
| Deck Width | The total width of the deck surface to be covered. | Feet | 8 – 40 ft |
| Deck Length | The length of the individual deck boards as they will be installed. | Feet | 8 – 20 ft |
| Board Width | The actual measured width of a single deck board. | Inches | 3.5″ – 5.5″ |
| Gap Width | The spacing between each deck board. | Inches | 0.125″ – 0.375″ |
Practical Examples
Example 1: Standard Rectangular Deck
Let’s say you’re building a standard backyard deck.
- Inputs:
- Deck Width: 14 feet
- Deck Length: 20 feet (you’re using 20-foot boards)
- Deck Board Width: 5.5 inches
- Gap Between Boards: 0.25 inches
- Calculation Steps:
- Effective Board Width = 5.5″ + 0.25″ = 5.75″
- Deck Width in Inches = 14 ft * 12 = 168″
- Number of Boards = 168″ / 5.75″ = 29.21. We must round up to 30 boards.
- Total Linear Feet = 30 boards * 20 ft = 600 linear feet.
- Result: You would need to purchase 600 linear feet of decking. A smart next step is to use a deck screw calculator to determine fastener needs.
Example 2: Small Platform Deck
Now consider a smaller, simpler platform.
- Inputs:
- Deck Width: 8 feet
- Deck Length: 12 feet
- Deck Board Width: 3.5 inches (for a 4-inch nominal board)
- Gap Between Boards: 0.125 inches
- Calculation Steps:
- Effective Board Width = 3.5″ + 0.125″ = 3.625″
- Deck Width in Inches = 8 ft * 12 = 96″
- Number of Boards = 96″ / 3.625″ = 26.48. Round up to 27 boards.
- Total Linear Feet = 27 boards * 12 ft = 324 linear feet.
- Result: You need 324 linear feet.
How to Use This Linear Feet Decking Calculator
- Enter Deck Width: Measure the width of your deck in feet. This is the dimension perpendicular to the direction your boards will run.
- Enter Deck Length: Input the length of the boards you plan to use, which should correspond to the length of your deck.
- Enter Board Width: Do not use the nominal size (e.g., “6-inch”). Measure the actual width of the board in inches (e.g., 5.5 inches). This is critical for an accurate linear feet decking calculator result.
- Enter Gap Size: Decide on your gap spacing in inches. 1/8 inch (0.125) is common for treated wood, while composite may require more.
- Interpret Results: The calculator instantly provides the total linear feet required. Always add a waste factor (5-15%) to this number to account for cuts, mistakes, and unusable board ends. The chart and table on this page provide guidance.
Key Factors That Affect Decking Needs
- Board Width: Narrower boards require more linear footage to cover the same area compared to wider boards.
- Gap Size: A larger gap reduces the number of boards needed, slightly decreasing the total linear feet.
- Deck Shape: This calculator is for rectangular decks. Irregular shapes or curves will require more cuts and thus a higher waste factor.
- Diagonal Installation: Installing boards at a 45-degree angle can increase material needs by 15-20% due to the angled cuts at both ends. Our square footage calculator can help with basic area, but you’ll need to add a significant waste factor for diagonal patterns.
- Material Defects: Some boards may have knots, splits, or warping that make portions unusable. A higher waste factor accounts for this.
- Project Complexity: Features like stairs, benches, or built-in planters will require additional material not covered by the main deck surface calculation.
Frequently Asked Questions (FAQ)
- 1. How much waste should I add for decking?
- A standard rule of thumb is 10%. For simple rectangular decks, 5-7% might be enough. For complex decks with diagonal patterns or multiple levels, 15-20% is safer.
- 2. Does this calculator work for diagonal decking?
- No, this is a basic linear feet decking calculator for perpendicular installations. For a 45-degree diagonal pattern, calculate the total as normal, then add an additional 15-20% to your final number.
- 3. What is the difference between linear feet and square feet?
- Square footage measures area (Length x Width), while linear footage measures total length only. Decking is sold by the linear foot, which is why this calculation is so important.
- 4. Why can’t I just use my deck’s square footage?
- Square footage doesn’t account for board width or gap spacing. Two decks with the same square footage will require different linear feet of material if one uses 4-inch boards and the other uses 6-inch boards. To understand the underlying structure, consult a joist span calculator.
- 5. What is the actual width of common deck boards?
- A nominal “5/4 x 6” board is typically 5.5 inches wide. A “2 x 4” is 3.5 inches wide. A “2 x 6” is 5.5 inches wide. Always measure your specific material before calculating.
- 6. Does the length of the boards I buy matter?
- Yes. You should buy boards that are equal to or longer than the “length” dimension of your deck to avoid seams (butt joints). If your deck is 14 feet long, buying 16-foot boards is ideal.
- 7. How do I calculate for a multi-level deck?
- Treat each rectangular section as a separate deck. Use the calculator for each section and add the results together.
- 8. Does this work for both composite and wood decking?
- Yes, the math is the same. Just ensure you use the correct board width and recommended gap size for your specific material, whether it is composite or wood. Researching composite vs wood decking can help you decide on the right gap.
Related Tools and Internal Resources
Once you have your material estimate, explore our other project planning tools to help complete your job.
- Decking Material Cost Estimator: Estimate the total cost of your project, including boards, fasteners, and finishing.
- Deck Screw Calculator: Determine the number and type of screws you’ll need for a secure installation.
- Joist Span Calculator: Ensure your deck’s substructure is safe and up to code by calculating correct joist spans.
- Square Footage Calculator: A simple tool for calculating the area of any rectangular space.
- How to Build a Deck: Our comprehensive guide takes you through the entire process from planning to finishing.
- Composite vs. Wood Decking: A detailed comparison to help you choose the right material for your budget and climate.