The three mid-density tiers
Sub 6, Sub 7 and Sub 8 of the NMFC density scale cover 8 to under 15 PCF. This is ordinary, well-packed commercial freight: cased beverages, boxed electronics and medical supplies at the light end; crated motors, boxed hardware, compressors and cast parts at the heavy end. It is also close to the density at which a dry van is balanced, about 11 PCF, which is why carriers price it near the middle of their rate tables.
| Sub | Class | Density | 48×40×48 pallet (53.33 cu ft) | 48×40×60 pallet (66.67 cu ft) |
|---|---|---|---|---|
| 6 | 100 | 8 to under 10 PCF | 427 to 533 lbs | 534 to 666 lbs |
| 7 | 92.5 | 10 to under 12 PCF | 534 to 639 lbs | 667 to 799 lbs |
| 8 | 85 | 12 to under 15 PCF | 640 to 799 lbs | 800 to 999 lbs |
The class steps here are small: 100 to 92.5 is a 7.5 percent drop in class factor and 92.5 to 85 is about 8 percent. In money terms the difference between adjacent classes on a mid-density shipment is often only a few percent of the bill, which is exactly why these classes are the easiest to fold into an FAK band.
Worked example: six pallets of boxed hardware at three weights
Six stackable 48 × 40 pallets built to 48 inches. Each pallet is 48 × 40 × 48 ÷ 1,728 = 53.33 cubic feet, so the shipment is 320 cubic feet. The class depends only on how much product goes on each pallet.
| Pallet weight | Shipment weight | Density | Class | Indicative bill, 750 mi | Per 100 lbs |
|---|---|---|---|---|---|
| 500 lbs | 3,000 lbs | 9.38 PCF | 100 | $465 | $15.50 |
| 600 lbs | 3,600 lbs | 11.25 PCF | 92.5 | $516 | $14.33 |
| 700 lbs | 4,200 lbs | 13.13 PCF | 85 | $553 | $13.17 |
The 600 lb build (3,600 ÷ 320 = 11.25 PCF) is the calculator preset on this page. It needs 240 lbs more across the shipment, or 3 inches less height per pallet, to reach 12 PCF and class 85. Six pallets at 48 inches double-stack into two rows, 8 linear feet, well under every carrier's linear rule and well under both cube triggers. This is the kind of shipment that class-rated LTL prices well.
The bill grows with weight but the cost per hundredweight falls as density rises. That is the economic argument for building full pallets: if a customer orders 3,000 lbs, shipping it on five full pallets rather than six partial ones raises density and lowers the rate.
Check where your mid-density load sits
- Safe — tariff cube, density and linear feet stay under the carrier's cube and linear-foot rules.
- Tier 1 — 350 cu ft or more under 3 PCF (XPO, Saia, ABF, Estes): synthetic weight of 6 lbs per tariff cubic foot.
- Re-bill — 750 cu ft or more under 6 PCF, or linear feet at the carrier's rule: book volume LTL or direct partial truckload.
How FAK bands are written for mid-density freight
FAK (freight all kinds) is a clause in a carrier pricing agreement that rates a range of actual classes at a single class. Mid-density freight is where most FAK bands sit, because shippers moving mixed SKUs want one predictable rate instead of a different class on every line. A typical structure looks like this:
| Actual class (from density) | Rated as | Comment |
|---|---|---|
| 50 to 85 | FAK 70 or 85 | Dense freight priced up slightly in exchange for a lower rate on lighter lines |
| 92.5 to 100 | FAK 85 or 100 | The band most mid-density shippers negotiate hardest |
| 110 to 175 | FAK 125 or actual | Often capped, often excluded |
| 200 to 500 | Actual class | Low-density freight usually left out of FAK entirely |
The bands above are an illustration, not a carrier's terms. When you negotiate:
- Bring your density profile, not your class history. Pull a quarter's shipments, compute density per line from real dimensions and weights, and show the carrier the distribution. A band built on measured density survives W&I inspections; one built on what the BOLs said does not.
- Read the density floor. Many FAK clauses only apply above a stated minimum density, commonly somewhere between 6 and 10 PCF. Below it, actual class applies.
- Read the exceptions. Cubic capacity, linear foot and volume shipments are usually carved out. The FAK exceptions page explains how those carve-outs work.
- Trade the band against the discount. A wider FAK band with a smaller discount can cost more than a narrow band with a deeper one if most of your freight is already class 85 or better.
The stacking trap: how a class 100 load gets cubed like class 175
Mid-density freight is safely above the 6 PCF Tier 2 cube line, until someone writes "do not stack" on it. Carriers cube non-stackable units at the 96-inch trailer ceiling. A 48-inch pallet cubed at 96 inches has half its real density.
| Eight 48×40×48 pallets, 500 lbs each | Stackable | Marked do-not-stack |
|---|---|---|
| Physical cube | 426.7 cu ft | 426.7 cu ft |
| Tariff cube | 426.7 cu ft | 853.3 cu ft |
| Density used by the cube rule | 9.38 PCF | 4.69 PCF |
| Over 750 cu ft at under 6 PCF? | No | Yes |
| Synthetic weight at 6 lbs per cu ft | n/a | 5,120 lbs |
| Linear feet | 8 LF | 16 LF |
| Indicative bill, ODFL lane, 750 mi | $620 | about $1,355 |
Same freight, same class 100, more than double the bill. The physical density (4,000 ÷ 426.7 = 9.38 PCF) never changed; the tariff cube doubled because 48 × 40 × 96 ÷ 1,728 = 106.67 cubic feet per pallet, and eight of those are 853.3. Under Old Dominion's ODFL 100 Item 610-1 the shipment is over 750 cubic feet at under 6 PCF, and at 16 linear feet it also crosses the 15-foot linear rule. Carriers reissue rules tariffs; the current issue governs. Unless the product genuinely cannot carry weight, put a flat, rigid top on it and leave the do-not-stack label off. The 96-inch rule page covers the details.
Cube thresholds at a glance for 8 to 15 PCF freight
- Tier 1 (350 cu ft at under 3 PCF): out of reach for stackable mid-density freight. Cubed to 96 inches, an 8 PCF pallet only drops under 3 PCF if it is shorter than 36 inches, so short non-stackable pallets are the exception to watch.
- Tier 2 (750 cu ft at under 6 PCF): out of reach while stackable. Once non-stackable units are cubed to 96 inches, tariff density is physical density × height ÷ 96: an 8 PCF pallet under 72 inches, or a 12 PCF pallet under 48 inches, falls below 6 PCF. Eight 48 × 40 units cubed to 96 inches make 853 cubic feet, past the 750 line; seven make 746.7.
- Linear-foot rules (12 to 15 LF): the real limit for this band. Eight stackable pallets at 48 inches fill 8 feet; twelve fill 12 feet; anything over 60 inches cannot be double-stacked and fills twice the floor.
Once a mid-density shipment passes about 5,000 lbs or 12 linear feet, a spot volume LTL quote is usually worth requesting alongside the class rate.
Mixed-SKU shipments: one bill, several classes
Most mid-density shippers do not send six identical pallets. A typical distribution order mixes dense and light lines on one bill of lading, and without an FAK clause each line is classed on its own density. Take the six 600 lb hardware pallets above (320 cubic feet, 11.25 PCF, class 92.5) and add two 48 × 40 × 60 pallets of boxed light fixtures at 450 lbs each. Each fixture pallet is 66.67 cubic feet, so that line is 133.3 cubic feet and 900 lbs: 6.75 PCF and class 125.
On actual-class pricing the carrier rates 3,600 lbs at class 92.5 and 900 lbs at class 125. It does not average the two lines into one density (4,500 ÷ 453.3 = 9.93 PCF would be class 100), and you cannot ask it to. Under an FAK band that rates 92.5 to 125 as one class, both lines rate the same, which is the whole attraction of FAK for mixed orders. Either way, list each commodity on its own line with its own count, dimensions and weight. Bills that lump everything into one line with one class are the ones inspectors open first.
Keep the numbers on the bill honest
Mid-density freight gets reclassified less often than light freight, but when it does the cause is nearly always the bill of lading: a class copied from an old routing guide, a weight that leaves out the pallet, a height measured to the top carton rather than to the top of the corner boards. A 48 × 40 pallet with 600 lbs on it is class 92.5 at 48 inches (11.25 PCF), class 100 at 56 inches (9.64 PCF) and class 125 at 70 inches (7.71 PCF). Measure the pallet as built, write the dimensions on every line, and follow the BOL dimensional checklist.