What size box do I need?
Most home and ecommerce shipments fit a short list of sizes: 6–8" cubes for small or round items, 12×12×6 and 14×14×6 for flat goods and apparel, 20×20×12 and 24×24×12 for bulky-but-light loads, and a wardrobe box for moving. Measure the item, add room to cushion, then match it below.
The sizes that cover most shipments.
| Small or round items — mugs, candles, a single bottle | 6×6×6 to 8×8×8 cube |
| Flat goods — apparel, books, vinyl records, frames | 12×12×6 · 14×14×6 |
| Bulky but light — blankets, comforters, bedding | 20×20×12 · 24×24×12 |
| Fragile items that need cushioning | +2 in clearance each side |
| Moving a wardrobe or hanging clothes | 20×20×45 wardrobe |
Find your box by what you're shipping
Pick what's going in the box. Each opens a full packing guide with exact sizes, board strength, and the cushioning that keeps it intact in transit.
Common box sizes, drawn to scale
These are the corrugated sizes that cover most shipments, shown at their true relative proportions. Every box is real and in the Packrift catalog — tap one to open it. Prices and stock live on the product page.
↕ Heights shown proportionally · single-wall ECT-32 unless a heavier load calls for double-wall ECT-48 · Browse all shipping boxes
How to measure for a box
Boxes are always listed inside length × width × height. Measure the item the same way, then leave room to cushion it.
Measure the item, not the old box
Length is the longest side, width the next, height the shortest. Round each up to the nearest inch.
Add room to cushion
Leave about 2" on every side for a fragile item so 1–2" of bubble or paper fits around it. A snug, non-fragile item needs far less.
Match to the next size up
Pick the nearest standard box that clears your padded dimensions. If the item is heavy for its size, step up to double-wall (ECT-48) board.
Check it doesn't bulge or rattle
Flaps should close flat with no doming, and a gentle shake should produce no shift. Either one means resize.
Cube, standard, flat, or long
Two boxes can hold the same volume and ship completely differently. Shape decides how a carrier bills it and how well it protects.
Cube
Equal sides. Best for round, dense, or awkward items — mugs, bottles, a bundled set. Fewer voids to fill.
Standard
Longer than tall. The everyday shipper for apparel, books, and mixed goods. Widest size range.
Flat
Wide and shallow. Frames, mirrors, laptops, layered clothing — anything that shouldn't stand on end.
Long / tube
Posters, art prints, and rolled goods ship in a mailing tube — never folded into a flat box.
The size you pick is a shipping bill
On small parcels, freight can rival the price of the product itself — and an oversized box is the most common reason. Carriers bill the greater of actual weight or dimensional weight, so empty space costs real money.
Right-size the box, fill the voids, and buy in case quantities so the freight spreads across more units. We publish the underlying numbers instead of hiding them.
Open the cost & cube index →example — a 20×20×12 box
= (20 × 20 × 12) ÷ 139
= 4800 ÷ 139 ≈ 34.5 lb billable
…even if the blankets inside weigh 8 lb.
Fewer, better-fitted boxes beat one big box with air in it. That's the whole game on thin-margin freight.
Box-size questions, answered
What is the most common shipping box size?
There isn't one universal size, but 12×12×6 and 14×14×6 cover a huge share of everyday ecommerce — apparel, books, framed goods, and mixed orders. For small or round items, a 6×6×6 or 8×8×8 cube is the workhorse. Keep a few of each on hand rather than forcing everything into one size.
How much bigger than my item should the box be?
For a fragile item, aim for about 2 inches of clearance on every side so 1–2 inches of cushioning fits around it. For sturdy, non-fragile goods, a snug box with minimal void is better — it uses less fill and ships smaller. When in doubt, size to the padded dimensions, not the bare item.
Is length, width, or height listed first?
Box dimensions are listed inside as Length × Width × Height. Length is the longest side of the opening, width the shorter side of the opening, and height the depth from the opening down. Measuring your item the same way makes matching a size straightforward.
When do I need a double-wall box?
Step up to double-wall (ECT-48) board when the contents are heavy for their size, when you're stacking or palletizing, or for anything you'd hate to see crushed — dense books, tools, glassware, or a heavy mixed load. Single-wall ECT-32 is fine for the majority of light-to-medium parcels.
Should I use a bigger box to be safe?
Usually no. Carriers bill on dimensional weight, so an oversized box raises your shipping cost and adds void you have to fill. Right-sizing the box is one of the cheapest ways to protect margin, especially on small orders where freight already runs high.
PACKRIFT · Right-size the box, spread the freight, ship it once. Confirm current dimensions and options on each product page before ordering.