18 × 14 × 8 box
volume & shipping weight
An 18 × 14 × 8 inch box holds 2,016 cubic inches — 1.167 cubic feet, or 33 liters. In metric it measures 45.7 × 35.6 × 20.3 cm.
What an 18x14x8 box bills at
Carriers charge the greater of actual weight and dimensional weight. For this box: 2,016 in³ ÷ 139 = 14.5 → 15 lb at FedEx, UPS Daily Rates and DHL; ÷ 166 = 12.14 → 13 lb at UPS Retail. If what’s inside weighs more than that, you pay the actual weight.
| Carrier / rates | Divisor | DIM weight | Billed at least | Note |
|---|---|---|---|---|
| FedEx (US) | 139 in³/lb | 15 lb | 15 lb | Fractions of an inch round up; weight rounds up to the next lb. |
| UPS Daily Rates | 139 in³/lb | 15 lb | 15 lb | Account rates. Dimensions round up to whole inches. |
| UPS Retail Rates | 166 in³/lb | 13 lb | 13 lb | UPS Store / counter, domestic. |
| USPS Priority Mail & Ground Advantage | 139 in³/lb | 15 lb | 15 lb | Over 1 ft³, so DIM applies. Each side rounded up to the inch first. |
| DHL Express (from the US) | 139 in³/lb | 15 lb | 15 lb | Rated in whole-lb steps. |
| International, rated in kg | 5,000 cm³/kg | 7 kg | 7 kg | For rates quoted in kg (e.g. shipping from Europe or Asia): 46 × 36 × 21 cm after rounding each side up to the cm. From the US, FedEx and UPS use 139. |
“Billed at least” includes any minimum billable weight the box’s size triggers. Actual weight still wins if it’s higher.
Rules verified 22 Sep 2026 · sources: FedEx Service Guide 2026 · UPS 2026 Rate and Service Guide (Daily Rates) · UPS 2026 Rate and Service Guide (Retail Rates) · USPS DMM 223 (Priority Mail: DIM weight, cubic, nonstandard fees) · DHL Express US Service & Rate Guide 2026
Size checks for 18 × 14 × 8 in
Longest side 18 in, girth 2 × (14 + 8) = 44 in, so length + girth is 62 in. Here’s how that sits against each carrier’s lines (size only — weight rules are separate).
- UPS & FedEx Additional Handling (size)Clear. Longest side 18 in: 30 in under the 48 in line. Second-longest 14 in: 16 in under the 30 in line. Length + girth 62 in: 43 in under the 105 in line. Volume: 8,352 in³ under the 10,368 in³ line.
- UPS Large Package / FedEx OversizeClear. Length + girth 62 in: 68 in under the 130 in line. Volume: 15,264 in³ under the 17,280 in³ line. Longest side: 78 in under the 96 in line.
- UPS & FedEx maximum sizeWithin the 108 in length and 165 in length + girth maximums.
- USPS size limitLength + girth 62 in is within USPS’s 108 in limit.
- USPS nonstandard feesNone for this size: longest side 18 in is not over 22 in and 2,016 in³ is not over 2 ft³ (3,456 in³).
- USPS Cubic pricing (commercial)Not eligible: 1.167 ft³ is over the 1 ft³ Ground Advantage Cubic maximum. Cubic calculator →
- DHL Express Oversize PieceClear: longest side 18 in (line: 40 in), second-longest 14 in (line: 32 in).
Rules verified 22 Sep 2026 · sources: FedEx Service Guide 2026 · UPS 2026 Rate and Service Guide (Daily Rates) · USPS DMM 101 (maximum size and weight) · USPS DMM 223 (Priority Mail: DIM weight, cubic, nonstandard fees) · USPS DMM 283 (Ground Advantage — Commercial, cubic) · DHL Express US Service & Rate Guide 2026
Trim one inch
The biggest saving comes from the height: 8 → 7 in drops the FedEx/UPS DIM weight from 15 to 13 lb.
| Change | in³ | DIM ÷139 | Saves | UPS Retail ÷166 | USPS |
|---|---|---|---|---|---|
| Length 18 → 17 in | 1,904 | 14 lb | −1 lb | 12 lb | 14 lb |
| Width 14 → 13 in | 1,872 | 14 lb | −1 lb | 12 lb | 14 lb |
| Height 8 → 7 in | 1,764 | 13 lb | −2 lb | 11 lb | 13 lb |
On a 48 × 40 pallet
6 per layer (3 × 2, 8 in side up), 7 layers in 60 in of stack height = 42 boxes, 49 ft³ in all. The layer covers 79% of the deck.
Assumes a simple column stack, box upright, no overhang, 60 in of boxes on the deck. Interlocked or mixed patterns can fit more; check your carrier’s or warehouse’s height limit. Try mixed patterns, other pallets and heights →
Size tier
Large standard at the lightest. Amazon sets the tier on the greater of unit weight and dimensional weight — here 2,016 ÷ 139 = 14.5 lb. It’s within 18 × 14 × 8 in and the DIM weight (14.5 lb) is under 20 lb.
Rules verified 22 Sep 2026 · sources: Amazon Seller Central — Product size tiers
Heavier contents can move it up a tier — check with your product’s weight. See the FBA dimensional weight guide for 2026 fees.
Too big for every USPS Flat Rate box — the roomiest are the Large Flat Rate Box (12 × 11 3/4 × 5 1/2 in inside) and Medium Flat Rate Box 2 (13 5/8 × 11 7/8 × 3 3/8 in inside).