Board Foot vs. Linear Foot: Understanding the Key Differences

When I first fell into the lumber industry, I found myself regularly being asked "how many linear feet of barnboard would be required for a wall?". Or "how many square feet would 20 board feet get me?". It seems to be a point of confusion for many, and it was essential to our success at The Knotty Lumber Co to develop a strong understanding of a board foot vs linear foot. It also became incredibly important for us to be able to explain what they were!

Ever had a confused look when someone throws around terms like "board feet" or "linear foot"? You're not alone. For anyone buying hardwood lumber—whether you're a contractor, a custom furniture maker, or a first-time DIYer—knowing the difference can save you money, time, and a whole lot of headaches. This guide will break it down so you can walk into any lumber yard with confidence.

What is a Board Foot?

A board foot is a measurement of volume, not length. It tells you how much wood you’re really getting in that piece of lumber—not just how long it is.

One board foot is equal to a piece of wood that is:

• 12 inches long
• 12 inches wide
• 1 inch thick

That’s 144 cubic inches of wood.

How to Calculate Board Feet

The formula in inches is:

(Length in inches x Width in inches x Thickness in inches) / 144 = Board Feet

The formula in feet is:

(Length in feet x Width in inches x Thickness in inches) / 12 = Board Feet

This calculation is important when buying dimensional lumber in bulk. It helps you compare price baselines between suppliers, quote jobs, and double-check project costs before purchase.

What is a Linear Foot?

A linear foot (or lineal foot) is a measurement of length only. It tells you how long a board is, regardless of its width or thickness.

So if a board is 10 feet long, that’s 10 linear feet—whether it’s 2 inches wide or 12 inches wide. Whether it’s 1 inch thick or 5 inches thick

How to Measure in Linear Feet

This one’s as straightforward as it gets: Generally you use a tape measure!

1 linear foot = 12 inches of length

You’re just measuring the length of the board. No math gymnastics here.

Board Foot vs Linear Foot: Key Differences

If we compare board feet and linear feet side by side:

The key takeaway? Board feet factors in width and thickness, which makes them ideal for pricing and estimating lumber for projects where volume matters like a countertop or stair treads. Linear feet, on the other hand, are great for trim jobs, or when calculating the cost of similar jobs.

When to Use Board Feet and When to Use Linear Feet

Understanding the difference between board feet and linear feet isn’t just technical—it can save you time, money, and frustration when sourcing lumber. These two units of measurement serve different purposes depending on the type of project and the way the wood is being sold. Remember, board feet measures volume, linear feet measures length only,

✅ Use Board Feet When:

·       Building a Dining Table from Rough-Cut Lumber
– You need to calculate how much 8/4 walnut you'll need to mill the top, legs, and aprons.

·       Ordering Live Edge Slabs for Custom Furniture
– The slabs vary in width and thickness, so you’re charged by board foot to reflect the full volume.

·       Purchasing Lumber for Custom Cabinet Doors
– You need specific thickness and width for frames and panels, and board footage gives an accurate material total.

·       Stocking Hardwood in Bulk for Resale
– As a supplier, you price inventory in board feet to reflect the full usable volume across species.

·       Quoting a Client for a Built-In Bookshelf
– You estimate how many board feet of lumber you’ll need for shelves, sides, and face frames.

✅ Use Linear Feet When:

• Installing Baseboards Around a Room
  – You're buying 3-1/4" baseboard stock that's all the same size—just measure the length of the walls.
  
  
• Ordering Trim or Crown Moulding
  – Standardized profile, consistent dimensions—cost is based on how many feet you need to wrap the space.
  
  
• Buying S4S (surfaced four sides) Pine for Shelving
  – You’re using pre-dimensioned 1x8s, and only care how many feet of board you'll need.
  
  
• Installing Cedar Deck Fascia
  – You're wrapping the deck perimeter with 1x6 cedar boards and calculating how many linear feet to cover.
  
  
• Running Shiplap Along a Wall
  – Since each piece is the same width and thickness, your focus is on total wall length for material coverage.

How Many Board Feet in a Linear Foot?

Ah, the golden question: How many board feet are in a linear foot?

The answer? It depends on the width and thickness of the board.

For example:

• A board that’s 1" thick and 6" wide has 0.5 board feet per linear foot
• A board that’s 2" thick and 12" wide has 2 board feet per linear foot

The difficulty in answering this question is the only way to find out how many board feet are in a linear foot, is to convert the specific piece to board feet!

Using a Board Foot Calculator

Let’s be honest… Math isn’t everyone’s favorite part of woodworking. That’s why we’ve made it simple with our Board Foot Calculator—a tool designed to take the guesswork out of lumber estimating so you can focus on the fun stuff: building.

Here’s how it works:

1.     Enter the quantity of boards you’re measuring (1 if there is only 1 piece, 2 if there is 2 and so on)

2.     Length – Enter the board’s length in either inches or feet (toggle between feet and inches by clicking “ft” or “in”.

3.     Width – Enter the board’s width in inches

4.     Thickness – Input the thickness in inches (commonly 1", 1.25", 2", etc.)

5.     Price per board foot (Optional, but convenient)

The calculator uses the standard formula:

(Length in inches × Width × Thickness) ÷ 144 = Board Feet

Or

(Length in feet × Width × Thickness) ÷ 12 = Board Feet

Once entered, you’ll instantly see the total number of board feet—no pencil, no scratch paper, and no double-checking required. This is especially helpful when you’re working with multiple boards or trying to compare costs across different species and sizes.

Whether you're pricing out rough lumber for a project, estimating yield from a slab, or planning your next stock-up, this tool ensures you get an accurate read every time. It's fast, accurate, and beginner-friendly—just the way lumber math should be.

👉 Try our calculator now!

Don’t Let Lumber Lingo Slow You Down

Still uncertain? That’s okay. Many builders and woodworkers had to learn the hard way. The good news? You don’t have to. You have tools and resources to guide you. We're here to help you make smart purchases and ultimately, successful builds.

If you’re shopping on our online lumber shop, knowing whether a product is sold by board foot will help you make informed buying decisions.

Conclusion: Which Measurement Should You Use for Your Project?

If your project depends on volume like a tabletop or stair tread stick with board footage. If you just need a certain length, like for trim or edge banding, linear feet is the way to go.

And remember, you can always double-check with our calculator or by reaching out to our team.

📐 Ready to purchase your lumber?

Need a hand? Get in touch and we’ll walk through it with you.

Pro Tip: If you’re ever stuck on whether you’re looking at one board foot, one square foot, or one linear foot, check your dimensions and give our calculator a whirl.

📏 Measure Twice. Estimate Properly. Build like a professional.