30 × 24 × 18 in box: dimensions, dim weight and strength
A 30 × 24 × 18 in box holds 12,960 in³ (7.5 ft³) inside. Made in C flute its outside is about 30.31 × 24.31 × 18.47 in, which dimensional weight bills USPS at 106 lb and FedEx at 94 lb.
Key numbers
| Inside (L × W × H) | 30 × 24 × 18 in |
|---|---|
| Inside volume | 12,960 in³ · 7.5 ft³ · 212.4 L |
| Inside, metric | 762 × 610 × 457 mm |
| Perimeter 2(L + W) | 108 in |
| Length + girth, C flute OD | 115.9 in |
Outside dimensions by flute
| Board | Caliper, in | Outside, in | Outside volume, ft³ |
|---|---|---|---|
| E flute | 0.063 | 30.13 × 24.13 × 18.19 | 7.649 |
| B flute | 0.125 | 30.25 × 24.25 × 18.38 | 7.8 |
| C flute | 0.156 | 30.31 × 24.31 × 18.47 | 7.877 |
| EB double wall | 0.188 | 30.38 × 24.38 × 18.56 | 7.953 |
| BC double wall | 0.281 | 30.56 × 24.56 × 18.84 | 8.186 |
OD ≈ ID + 2 calipers on length and width, + 3 on depth. An estimate: your box maker sets the scores. Convert other sizes.
Dimensional weight
| Carrier | Divisor | Measured, in (C) | DW, C flute | DW, BC double wall |
|---|---|---|---|---|
| USPS | 139 | 31 × 25 × 19 | 106 lb | 106 lb |
| FedEx | 139 | 30 × 24 × 18 | 94 lb | 106 lb |
DW = ⌈L × W × H ÷ divisor⌉ on outside dimensions, after each carrier's own rounding. USPS applies it only above 1,728 in³ (n/a means it bills actual weight). The carrier bills the greater of actual and dimensional weight. Divisors checked on carrier pages 2026-10-27; try your own weight.
Estimated compression strength
| Board | BCT, lbf | After 30 days storage |
|---|---|---|
| 32 ECT B flute | 690 | 414 |
| 32 ECT C flute | 772 | 463 |
| 44 ECT C flute | 1,061 | 637 |
| 48 ECT C flute | 1,157 | 694 |
| 48 ECT BC double wall | 1,553 | 932 |
| 61 ECT BC double wall | 1,974 | 1,184 |
| 71 ECT BC double wall | 2,297 | 1,378 |
Simplified McKee: BCT ≈ 5.87 × ECT × √(caliper × 108). The 30-day column applies Packgent's default 40% storage loss, an assumption. Estimates only; test with ASTM D642.
Pallet pattern on 48 × 40
| Board | Per layer | Layers | Boxes per pallet | Load height, in | Cube used |
|---|---|---|---|---|---|
| C flute | 1 | 2 | 2 | 42.4 | 26% |
| BC double wall | 1 | 2 | 2 | 43.2 | 27% |
Column stacked, no overhang, on a 48 × 40 in deck 5.5 in tall, loaded to 60 in overall. Those three are assumptions you can change in the pallet calculator. Pattern: 24.3125″ along the 48″ side.
Blank size in C flute
| Style | Blank, in | Board, ft² |
|---|---|---|
| 0201 RSC | 109.88 × 42.31 | 32.29 |
| 0200 HSC | 109.88 × 30.16 | 23.01 |
| 0203 FOL | 109.88 × 66.31 | 50.6 |
With one caliper allowance per score. Multiply board area by your board's combined weight (lb/MSF ÷ 1,000) for box weight, or use the box weight calculator.
Sources
- USPS Domestic Mail Manual 223 (Priority Mail prices and eligibility), section 1.4
- FedEx: What is dimensional weight?
- Flute calipers: Foster (1997), Wiley Encyclopedia of Packaging Technology
- McKee, Gander & Wachuta (1963), Paperboard Packaging 48(8)
Last reviewed . See all sources and how Packgent computes.
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