The invoice gap nobody explains
Gross Tally vs Net Tally Lumber
Gross tally counts board feet when lumber is rough and green; net tally counts it after drying and surfacing. Net is smaller — usually by 6–12% — so the basis your dealer uses can quietly change your bill on the very same stack of wood. It's the reason your own board foot tally can be correct and still miss the invoice.
The first time a net-versus-gross tally bit me, I'd done everything right at my desk and still came up short reconciling the invoice. I hadn't asked which tally the price was quoted on. That one missed question is, in my experience, behind most "the yard overcharged me" complaints I hear — and once you know to ask it, the mystery evaporates.
What does each tally measure?
Hardwood gets measured for board feet at a specific point in its life, and that point decides the number:
- Gross tally (rough green): measured at the sawmill before kiln drying, at full rough thickness and width. The largest count.
- Net tally (dried & surfaced): re-measured after the wood has shrunk in the kiln and been planed. Smaller, and closest to what you can actually use.
Two honest dealers can hand you the same lift and quote different board feet simply because one tallied gross and the other net. Neither is cheating. But if you don't know which basis you're being charged on, you can't compare two prices fairly — you'd be comparing a green number to a finished one.
Why does the gross tally read higher than net?
Two physical processes shrink the count between gross and net:
- Kiln-drying shrinkage — green wood loses moisture and contracts in width and thickness, typically a few percent.
- Surfacing — planing to a smooth, consistent thickness removes more material, the same loss laid out in the hardwood thickness guide, where 4/4 finishes near 13/16″.
Add them together and a lift tallied gross can read 6–12% higher than the identical lift tallied net. On a $2,000 walnut order, that's $120–$240 of difference riding on a single word — which is exactly why the basis belongs in the conversation before you agree to a price.
Is the loss 7% or 8%? Why every source says something different
Search this topic and you'll find dealers publishing 7%, others 8%, and a third group quoting "8% for drying plus another 10% at the planer." None of them is lying. They're each describing a different pair of measurement points, and the gap grows every time you move the finish line:
| From → To | What gets removed | Typical loss |
|---|---|---|
| Green rough → kiln-dried rough | Moisture shrinkage only (width and thickness) | 6–8% |
| KD rough → S2S surfaced | Planing removal to an even thickness | 4–6% at 4/4 |
| Green rough → surfaced & dry | Both of the above, stacked | 9–13% |
That's the whole disagreement: a "7%" figure normally describes one of those hops, while "8% plus 10%" describes both in sequence. Goodwood, a Canadian mill, traces its 8% and 10% numbers to a 1977 National Conference on Weights and Measures paper on tallying sawn lumber (their explanation is here) — a useful citation, but read it as tolerance practice for green stock, not a promise about your invoice.
The other half of the confusion is where a mill starts its "gross" count. Some tally truly green at the saw; others tally at air-dried rough, which has already given up most of its shrinkage before the number is written down. Start at air-dried rough and your gross-to-net gap is only the planing row, 4–6%. Start green and it's 9–13%. Same stack, same honest dealer, two different published percentages.
For the buyer in the yard, the practical read is this: 6–8% is normal when only one hop is in play, and 9–13% is normal across the full green-to-finished distance. If a dealer tells you a stack lost 4% green to surfaced, ask which two points they measured — and if they can't answer that, treat the number as marketing.
One more translation note, because metric sources muddy this further: 1 board foot is 0.00236 m³, so 1 m³ is about 423.8 board feet. When you read a mill's figure quoted in cubic metres, convert it before comparing it to your BF tally — that's where a lot of "the American number looks wrong" threads come from.
What does the gap look like on a real invoice?
Here's a case from my own files, numbers rounded. I tallied a pack of kiln-dried, surfaced soft maple at 208 net board feet by tape at the rack. The invoice came back at 228 board feet — about 9.6% higher. Nothing was wrong: the mill priced it on the gross green tally taken before drying and surfacing, which puts it inside the 9–13% full-hop row above. The reverse read is just as useful: 208 ÷ 228 means the pack lost 8.8% of its footage between the saw and my truck.
What mattered was the per-foot price. At a gross tally, the rate should sit lower to offset the bigger count. When I divided the total dollars by my net 208 BF, the effective net price was still fair, so I confirmed the basis and paid without argument. Treat that ~9.6% as one real data point from my desk, not a rule — I've seen the gap sit at 4–6% when the mill's gross was taken at air-dried rough, and bump past 12% on heavy surfacing. If your tally and the bill diverge, the full list of causes is in why the yard charged more.
How do you read a tally line on an actual invoice?
Most hardwood invoices don't print the words "gross" or "net." You have to infer the basis from four fields, so read them in this order rather than going straight to the total:
| Field on the line | Example entry | What it tells you |
|---|---|---|
| Description | RGL hard maple, KD S2S | Dry and surfaced. If the stock is finished but the count looks high, it was tallied before the kiln. |
| Call | 4/4 | Names the rough thickness target. A 4/4 call plus a full-inch figure in the count means rough measure, not surfaced. |
| BF | 228 | The billed footage. Compare it against your own tape tally (mine was 208) before you look at any price. |
| Rate | $5.00 | Price per billed BF. On a gross basis this number is always the smaller of the two. |
| Amount | $1,140.00 | BF × rate. Divide it by your net count for the price you actually paid: $1,140 ÷ 208 = $5.48/net BF. |
The line above has no "basis" column, and that's the point: the basis is the one field a tally invoice almost never states. You reconstruct it from the description plus the size of the count, or you ask. When I reconcile a pack I write the effective net rate ($5.48 in this case) at the top of my own sheet, because that's the only number comparable to the next dealer's quote.
How do you ask for a quote that's comparable?
Rewrite the RFQ so the answer forces the basis out. Five lines, copied from the email template I send to new mills:
| Ask for | Say this in the RFQ | Why |
|---|---|---|
| Tally basis | "Quote on net tally, KD S2S, or state the basis." | Removes the one word that makes quotes incomparable. |
| Rate per BF on that basis | "Give $/BF on the same basis as the count." | Stops a low count paired with a padded rate. |
| Average width and length | "State average width and average run length per grade." | The same footage can arrive as ten boards or thirty; the averages tell you which you're buying. |
| Grade and rules | "FAS one-face, NHLA rules, or specify." | Grade decides the usable percentage, not just the rate. |
| Shrinkage and surfacing tolerance | "What loss do you allow between green and shipped?" | A mill that answers instantly tallies honestly; a vague answer is your cue to slow down. |
How do you tell which tally you're getting?
"Is this tally gross or net?" A reputable dealer answers instantly. If the lumber is kiln-dried and surfaced (KD S2S), expect to be billed net tally — if it's quoted gross, the price per board foot should be lower to compensate. When the answer is vague, that's your signal to slow down.
This is exactly why I built the hardwood board foot calculator to round the way dealers do, so your estimate lands near the invoice instead of below it. Put the gross-versus-net question at the very top of your buying routine, and the surprise stops happening.
Frequently asked questions
What is the difference between gross tally and net tally?
Gross tally is board footage measured when lumber is rough and green, before drying and surfacing. Net tally is measured after the wood is dried and surfaced, so it's smaller. Buying on gross tally means paying for board feet that were later planed away.
How big is the difference between gross and net tally?
Typically 6–12% for kiln-dried, surfaced hardwood. Drying shrinkage accounts for part and surfacing the rest, so the same lift can carry two noticeably different board foot counts.
How do I know if I am being charged gross or net tally?
Ask the dealer directly. KD S2S lumber is usually billed net tally. If it's quoted gross, the price per board foot should be lower to offset the larger count, so confirm the basis before comparing two quotes.
Why do some sources say 7% loss and others 8% plus 10%?
They're measuring different hops. Drying alone (green rough to kiln-dried rough) runs 6–8%; planing to surfaced adds another 4–6%; the full green-rough to finished-net difference is 9–13%. A source quoting "8% plus 10%" is describing both hops at once.
Is gross tally or net tally better for the buyer?
Neither basis is unfair on its own. Divide the invoice total by the net board feet you can actually use and compare that effective rate across quotes — a bigger gross count at a lower rate can still cost less than a small net count at a padded rate.