Calculate board feet for one board or an entire lumber order. Add multiple boards with different dimensions.
7 Tips for Calculating Board Feet: A Beginner’s Guide
Tip 1: Understand What a Board Foot Actually Measures
A board foot is a unit of volume, not length, equal to a board that’s 12 inches wide, 12 inches long, and 1 inch thick, or 144 cubic inches of wood. Because it accounts for thickness as well as width and length, a board foot measurement stays accurate whether you’re pricing a stack of thin 1 inch boards or a handful of thick 8/4 slabs.
Tip 2: Know Why Board Feet, Not Linear Feet, Is How Rough Lumber Is Priced
Rough and specialty hardwood lumber is typically priced by the board foot rather than by linear foot, because thickness varies so much between species and cuts that linear footage alone doesn’t tell you how much actual wood you’re buying. Two boards of the same length and width but different thickness contain very different volumes of wood, and board feet is what lets you compare their price fairly.
Tip 3: Enter Actual Board Dimensions, Not Nominal Sizes
Enter the actual measured dimensions of your lumber, not the nominal size printed on a price tag or stated by a mill, since rough-sawn lumber is frequently sold close to its true thickness while dimensional or surfaced lumber is often noticeably smaller than its nominal size after milling. A board sold as 4/4 (four quarters, or one inch nominal) rough lumber, for example, often measures close to a true inch, while the same nominal size after surfacing on both faces can measure closer to 13/16 inch.
Tip 4: Use the Multi-Board Feature for a Full Lumber Order
The calculator lets you add multiple boards with different thickness, width, and length using the Add Another Board button, which is useful for totaling an entire lumber order in one pass rather than calculating each board separately and adding the results by hand. Remove any board entry you no longer need with its individual Remove button.
Tip 5: Choose a Waste Factor That Matches Your Project’s Complexity
The calculator’s Waste Factor options are None, 10%, 15%, and 20%, with 10% noted as standard for straight cuts and 15-20% recommended for more complex projects. A simple project with long, straight rip cuts wastes very little material, while a project with lots of short parts, angled cuts, or figure-matching for grain and color needs a higher waste factor to account for material lost to cutoffs and selective matching.
Tip 6: Enter Your Board Dimensions in the Calculator
Enter the Thickness, Width, and Length for each board in your order, adding as many board entries as you need for boards of different sizes. The calculator returns your Net Board Feet before waste, your total With Waste for ordering, and your Number of Boards, giving you a single total to take to the lumberyard.
Tip 7: Avoid the Most Common Board Foot Mistakes
Common mistakes include entering nominal lumber dimensions instead of actual measured dimensions, forgetting to add a waste factor and ordering exactly the net amount with no margin for mistakes or defects, and calculating each board separately instead of using the calculator’s multi-board feature and accidentally leaving one board out of the total. Measure a sample board from your actual stack before entering dimensions if you’re not certain whether it’s true to its nominal size.
Where to Go From Here
Now that you understand what a board foot measures, why actual versus nominal dimensions matter, and how to budget for waste, use our Board Feet Calculator to get your exact total before you place a lumber order. You’ll know your order accounts for every board and enough margin to finish the project.
Frequently Asked Questions About Calculating Board Feet
What exactly is a board foot?
A board foot is a unit of volume equal to a board 12 inches wide, 12 inches long, and 1 inch thick, or 144 cubic inches of wood. Unlike a linear foot, which only measures length, a board foot accounts for thickness and width too, which is why it’s the standard way rough and specialty lumber gets priced and ordered.
Should I enter the nominal size of my lumber or its actual measured size?
Enter the actual measured dimensions whenever possible, not the nominal size printed on a price tag. Rough-sawn lumber often measures close to its true nominal thickness, but dimensional or surfaced lumber is frequently smaller after milling – a board sold as one inch nominal after surfacing on both faces often measures closer to 13/16 inch. Measuring a sample board from your actual stack gives you the most accurate total.
How much extra should I order to account for waste?
The calculator’s guidance is that 10% is standard for straightforward projects with long, simple cuts, while 15-20% is more appropriate for complex projects with lots of short parts, angled cuts, or grain and color matching that requires being selective about which sections of a board you actually use.
Can I calculate board feet for an entire lumber order at once, not just one board?
Yes. Use the Add Another Board button to enter the thickness, width, and length for each board in your order, and the calculator totals them together into your Net Board Feet, With Waste amount, and Number of Boards, so you get one combined total instead of adding up individual calculations by hand.
Why does board thickness matter so much for pricing compared to just width and length?
Because a board foot is a volume measurement, thickness has just as much effect on the total as width or length does. A thick 8/4 board contains roughly twice the volume, and therefore roughly twice the board feet, of a same-sized 4/4 board of the same width and length, which is exactly why lumber priced by the board foot accounts for thickness rather than just linear footage.