There's nothing worse than standing in the lumber aisle doing math on your phone, second-guessing whether 47 boards is enough or if you should grab 50 "just in case." And then there's the drive home wondering if you just spent $200 more than you needed to.
This lumber calculator takes care of all that. Punch in your board dimensions, how many pieces you need, and the price—you'll instantly see your total length, total volume, and exactly what the whole order will cost. No mental math, no spreadsheets, no surprises at checkout.
Whether you're pricing out materials for a client quote, figuring out if that lumber will fit in your truck, or just trying to stick to a budget on a weekend project, this tool gives you real numbers to work with.
What You'll Get From This Calculator
Most lumber calculators stop at board feet. This one goes further because, honestly, board feet aren't always what you need to know.
Total Length – All your pieces laid end to end. Sounds simple, but it's useful when you're figuring out how many cuts you'll make or whether that delivery will fit through your garage door laid flat.
Total Volume – The actual cubic measurement of all your wood combined. This matters more than people realize. Volume tells you about weight (important for delivery and transport), storage space, and gives you a true apples-to-apples comparison when boards come in different sizes.
Total Cost – The number your wallet cares about most. Multiply your quantity by price per piece and see the damage before you commit. Works great for comparing suppliers too—run the same order through with different prices and see who's actually cheaper.
The calculator handles metric units (mm, cm, m) and spits out volume in whatever unit makes sense for you—cubic centimeters for a small woodworking project, cubic meters for a truckload of framing lumber.
A Quick Word About Lumber Measurements
If you've ever felt confused by lumber measurements, you're not alone. The industry uses about four different systems depending on who you're buying from and what you're building.
The Volume Approach (What This Calculator Uses)
Volume is the most straightforward measurement: length × width × thickness = how much wood you have. It's honest math that works anywhere in the world.
A piece of lumber 2,000mm long, 200mm wide, and 50mm thick contains 20,000,000 cubic millimeters—or 20,000 cubic centimeters, or 0.02 cubic meters. Same amount of wood, different ways to express it.
Board Feet (The North American Standard)
Walk into a hardwood dealer in the U.S. or Canada and they'll quote you in board feet. One board foot equals 144 cubic inches—picture a piece of wood 12" × 12" × 1" thick.
The formula: (Thickness in inches × Width in inches × Length in feet) ÷ 12
Board feet exist because they let you fairly compare lumber of different sizes. A thick, narrow board and a thin, wide board with the same board footage contain the same amount of wood.
Linear Feet (Retail Lumber)
Hardware stores keep it simple: they charge by the piece or by length. A 10-foot 2×4 is 10 linear feet, period. Thickness and width don't factor in because every 2×4 is the same size.
This works fine when you're buying standard dimensional lumber off the rack. Gets tricky when comparing different-sized boards.
The Nominal vs. Actual Trap
This one gets everyone the first time. That "2×4" you're buying? It's actually 1.5" × 3.5". The "2×4" name refers to the rough-cut size before the lumber gets dried and planed smooth. By the time it hits the shelf, it's shrunk.
What It's Called | What It Actually Measures |
|---|---|
2×4 | 1.5" × 3.5" (38mm × 89mm) |
2×6 | 1.5" × 5.5" (38mm × 140mm) |
2×8 | 1.5" × 7.25" (38mm × 184mm) |
2×10 | 1.5" × 9.25" (38mm × 235mm) |
2×12 | 1.5" × 11.25" (38mm × 286mm) |
4×4 | 3.5" × 3.5" (89mm × 89mm) |
For rough estimates, nominal dimensions are fine. If you're doing finish carpentry where an eighth of an inch matters, use actual dimensions.
How to Use This Calculator
Step 1: Enter Your Quantity
How many identical pieces do you need? If your cut list shows 24 shelf boards, enter 24. Running multiple sizes? Calculate each size separately and add up the totals.
Step 2: Plug In Your Dimensions
Enter the length, width, and thickness of one piece. Pick the right unit from the dropdown—mm, cm, or m. Tip: if you're working from a plan in inches, multiply by 25.4 to convert to millimeters.
Step 3: Add Your Price Per Piece
Check your supplier's current pricing. Online prices often differ from in-store, and prices vary between locations of the same chain. A quick phone call can save you from sticker shock.
Step 4: Pick Your Output Units
Choose how you want volume displayed. For furniture projects, cubic centimeters usually makes sense. For construction-scale orders, cubic meters keeps the numbers manageable.
Step 5: Read Your Results
You'll see total length, total volume, and total cost—everything you need to plan your purchase and budget.
Real-World Examples
Building a Backyard Deck
You're building a 12' × 14' deck and your plan calls for 42 deck boards, each 14 feet long. You're using 5/4×6 pressure-treated decking (actual dimensions: 1" × 5.5").
Calculator Inputs:
- Quantity: 42 pieces
- Length: 4,267mm (14 feet)
- Width: 140mm (5.5 inches)
- Thickness: 25mm (1 inch)
- Price: $18.50 per board (current big-box price for premium treated)
Results:
- Total length: 179.2 meters (588 linear feet)
- Total volume: 627,592 cm³ (about 0.63 cubic meters)
- Total cost: $777
That volume number tells you something useful: 0.63 cubic meters of pressure-treated lumber weighs roughly 500-550 lbs. Good to know if you're picking it up yourself.
Pro tip: Order 46-48 boards instead of 42. You'll lose at least one to a bow or twist that's too bad to use, and you want extras for cutting around knots that land in visible spots.
Floating Shelves for a Home Office
You're making six floating shelves from 3/4" walnut plywood, each 36" long and 10" deep.
Calculator Inputs:
- Quantity: 6 pieces
- Length: 914mm (36 inches)
- Width: 254mm (10 inches)
- Thickness: 19mm (3/4 inch)
- Price: $32 per piece (cut from larger sheets at $85 per 4×8 sheet)
Results:
- Total length: 5.48 meters
- Total volume: 26,449 cm³
- Total cost: $192
That volume is tiny—about 0.026 cubic meters—which is why these shelves will feel surprisingly light when you hang them.
Framing a Garden Shed
Your 8' × 10' shed needs framing lumber: thirty-two 2×4 studs at 8 feet, plus six 2×6 boards at 10 feet for the floor joists.
2×4 Studs:
- Quantity: 32 pieces
- Dimensions: 2,438mm × 89mm × 38mm
- Price: $5.75 each
Results: Total cost $184, volume of 264,038 cm³
2×6 Joists:
- Quantity: 6 pieces
- Dimensions: 3,048mm × 140mm × 38mm
- Price: $11.25 each
Results: Total cost $67.50, volume of 97,374 cm³
Combined framing cost: $251.50 for roughly 0.36 cubic meters of lumber—which weighs about 180-200 lbs dry.
Insider Tips for Smarter Lumber Buying
The 15% Rule (Minimum)
Always order at least 15% more than your calculations show. Here's where that extra goes:
- Saw kerfs: Every cut eats 1/8" of material. Make 50 cuts and you've lost over 6 inches of wood.
- Defects: Even in premium grades, you'll find boards with checks, knots in bad spots, or warps that showed up after stacking.
- Oops cuts: Measure twice, cut once—but you'll still make mistakes. Everyone does.
- Future you: That extra board in the garage is a lifesaver when you need to replace a damaged piece two years from now.
For rough-sawn lumber or lower grades, bump that to 20-25%.
Timing Your Purchase
Lumber prices swing with the seasons. Spring brings construction season and higher demand—prices typically peak from March through June. If you can wait, fall purchases (September through November) often save 10-15%.
The Art of Board Selection
Spend an extra 20 minutes at the lumber yard picking through the stack. You're looking for:
- Straight edges: Sight down the length like you're aiming a rifle
- No twists: Lay the board flat and check that all four corners touch
- Crown direction: Slight bows are normal—just make sure they all bow the same way so you can install them consistently
- End checks: Small cracks at the ends are common but mean you'll lose a few inches to trimming
The boards on top of the pile have been handled more and are often the worst. Dig down to the middle of the stack for the good stuff.
Price Shopping Actually Pays Off
I've seen the same 2×4×8 priced at $4.87, $5.75, and $7.29 at three stores within 10 miles of each other—on the same day. For a 50-board order, that's the difference between $243 and $364.
Get quotes from:
- Big box stores (often cheapest for dimensional lumber)
- Local lumber yards (better selection, especially for hardwoods)
- Contractor supply houses (if you buy enough, they'll deal)
That $500 lumber order might actually cost $600 once you factor in:
- Delivery fees: Usually $50-150 depending on distance
- Sales tax: 6-10% depending on your state
- Fasteners and hardware: The screws for that deck might run $80-120
- Sealers and stains: Treating lumber adds $1-3 per board in materials
Budget for the full project, not just the wood.
The Math Behind the Calculator
For the curious, here's what's happening under the hood:
Total Length = Quantity × Length of one piece
Total Volume = Quantity × (Length × Width × Thickness)
Total Cost = Quantity × Price per piece
All calculations maintain precision through unit conversion, with results displayed to two decimal places.
Supported Units
Input dimensions: millimeters (mm), centimeters (cm), meters (m)
Output volume: cubic millimeters (mm³), cubic centimeters (cm³), cubic meters (m³), liters (l)
Disclaimer
This calculator provides estimates for planning purposes. Actual material needs may vary based on cutting patterns, waste, defects, and project changes. Always verify quantities with your supplier and consider ordering extra material for large projects.