How Many Board Feet in a 2x10?

When a 2x10 shows up on my order, it's usually because something has to span — a beam, a long joist, a stair stringer. These are the pieces that hold the structure up, so at 1.667 board feet per foot they're also the line items I double-check hardest. The per-foot rate is just the nominal cross section over twelve; if you want to see why that ratio holds for every length, it's worked through in the how to calculate board feet guide.

How many board feet are in a 2x10 by length?

A 2x10 packs the most wood per foot of any board on this set of pages — 25% more than a 2x8:

The clean one to memorize is 12 ft = 20 BF. From there, every 6 ft adds 10 board feet.

Why does a 2x10 measure 9¼ inches?

Like the 2x8, a 2x10 is a wide board, so surfacing trims ¾″ off the width and it finishes at 9.25″ — not 9.5″ and certainly not the nominal 10. That actual width matters when you're sistering onto an existing joist or matching a stair rise, but the board feet stay pinned to the nominal 2×10 because softwood is sold that way. The rule for which boards lose ½″ versus ¾″ is spelled out in nominal vs actual dimensions.

How many board feet are in a built-up 2x10 beam?

Beams are where 2x10 board feet stack up literally. A built-up beam is just two or three 2x10s nailed or bolted together, so you add a full ply's worth of footage each time. Take a 3-ply beam, 16 ft long, carrying a deck:

• 3 plies × 16 ft = 48 linear feet of 2x10.
• 48 ft × 1.667 BF/ft = ~80 board feet in that one beam.

At a wide-stock rate near $0.90 per board foot (a planning estimate; long, wide 2x10 carries a premium) that beam is about $72 in lumber. Stack a couple of those plus the joists they carry and a deck frame climbs quickly — which is exactly why I tally the beams, joists, and rim in the cut list calculator and price the total in the lumber cost calculator before ordering.

One caution before you quote a client off that figure: the 80 BF is the billed number, worked from the nominal 2 × 10 the price list uses. The lumber you can actually sand is 1.5″ × 9.25″ = 1.156 BF per foot, so those same 48 feet are 55.5 board feet of wood — the nominal count runs 44% higher. You pay the 80; you glue up the 55.5. Neither number is wrong, but mixing them across two quotes is how a beam ends up costing more than the drawing said.

What are 2x10s used for?

The 2x10 lives in the structural backbone: long-span floor joists, deck beams (usually doubled or tripled), door and garage headers, and stair stringers where the 9¼″ depth gives room to cut the notches. It's also one of the heavier sticks to handle — a dry 16-footer runs around 48 lb, more when green or treated, which is its own reason to count carefully before a delivery. Need a shallower joist? A 2x8 covers shorter spans at lower cost per foot.

When is a triple 2x10 cheaper than an LVL?

On short deck beams under about 12–14 ft, three 2x10s often beat a single LVL on price and lead time at a local yard. Past that span, or when depth is limited by headroom, engineered lumber usually wins. Always check the span tables for your load and species — board feet tell you cost, not capacity. I price both options in the cost calculator before I commit.