Container questions, answered straight

The two worldwide standards are 20ft (20' × 8' × 8'6") and 40ft (40' × 8' × 8'6"), plus the 40ft high cube at 9'6" tall. Around them sit 10ft, 20ft HC, 45ft HC and — in North America only — 48ft and 53ft domestic boxes. All ISO boxes are exactly 8 feet wide.

Externally 20' × 8' × 8'6" (6.06 × 2.44 × 2.59 m). Inside you get 19'4" × 7'8" × 7'10" — 1,172 cubic feet, about 150 sq ft of floor. The door opening is 7'8" wide × 7'6" tall.

All ISO ocean containers are exactly 8'0" (2.438 m) wide — it's the one dimension that never varies. The exceptions never sail: US domestic 48ft and 53ft boxes are 8'6" wide, and European pallet-wide containers are about 2.5 m.

Standard boxes are 8'6" (2.59 m) tall; high cubes are 9'6" (2.90 m). Inside that means roughly 7'10" and 8'10" of clear height respectively — the extra foot matters most in conversions, where insulation eats 3–6 inches.

About 300 sq ft (27.8 m²) — internally 39'6" × 7'8". Two 40-footers side by side give you a genuine one-bedroom footprint of 600 sq ft.

A high cube (HC) container is one foot taller than standard: 9'6" external instead of 8'6". Same length, same width, same max gross weight — just 12–14% more volume. Nearly all new 40ft production is high cube.

A 20ft holds 33.2 cbm (1,172 cuft); a 40ft standard holds 67.7 cbm (2,390 cuft); a 40ft high cube holds 76.3 cbm (2,694 cuft). Real-world loading typically achieves 85–90% of these figures.

A 20ft fits 10 standard US (GMA 48"×40") pallets or 11 Euro pallets in one layer. A 40ft fits 21 GMA or 25 Euro pallets. A 53ft domestic box takes about 30 GMA pallets thanks to its extra 6 inches of width.

Standard boxes: 7'8" wide × 7'6" tall (2.34 × 2.28 m); high cubes give 8'6" of door height. If your cargo is taller than 7'6", you need a high cube or an open top.

Empty (tare): a 20ft weighs about 4,850 lb (2,200 kg); a 40ft standard about 8,000 lb (3,630 kg); a 40ft high cube about 8,750 lb (3,970 kg). Both 20ft and 40ft are rated to the same 67,200 lb (30,480 kg) max gross.

A 20ft can legally carry about 62,350 lb (28,280 kg) of cargo; a 40ft about 59,200 lb — the 20ft actually wins on payload because its own steel weighs less. On US highways, road limits (~44,000 lb of cargo) bind before the box does.

Tare is the empty box; payload is the cargo it may carry; max gross = tare + payload, the total rated weight stamped on the CSC plate on the door. For most modern boxes max gross is 30,480 kg (67,200 lb).

Yes — that's the whole point of the corner castings. At sea they stack 9–11 high; on land a static, well-founded stack of 2–3 is routine. Weight passes through the four corner posts, so stacks must align casting-to-casting, never mid-span.

The roof sheet itself is only rated for about 660 lb (300 kg) over a small area — it's the corner posts that are strong, each taking over 210,000 lb. Walk gently on a roof; build roof decks on frames that land the load on the castings.

In the US in 2026: used 20ft $1,500–3,000; used 40ft $2,000–4,500; new (one-trip) 20ft $2,500–5,500; new 40ft HC $4,000–7,000. Delivery adds 15–40%. Working 40ft reefers run $8,000–12,600 used.

$1,500–2,500 for a used cargo-worthy unit, $2,500–3,500 for premium used, $3,000–5,500 for a one-trip. Below $1,500 expect significant rust or a scam — pay by card, never wire transfer to an unknown seller.

One-trip: made one loaded voyage, near-new. Cargo-worthy (CW): certified structurally fit for shipping. Wind & watertight (WWT): sealed but not certified — fine for storage. As-is: expect holes, rot or door problems. For conversions, buy one-trip or high-grade CW.

Four channels: national online retailers (Container One, Boxhub, Western Container Sales), regional depots (cheapest delivery), leasing-company sell-offs, and marketplaces like eBay or Facebook (highest scam risk). Always confirm the exact unit number and inspect or get dated photos before paying.

Rental runs $75–250/month for storage boxes. If you need it longer than 18–24 months, buying usually wins — a used 20ft at $2,000 pays for itself vs $100/month rent in under two years, and you keep resale value of roughly 50–70%.

Yes, unusually well: a well-kept used box typically resells for 50–80% of its purchase price years later. Container prices track steel and freight cycles, so buying in a freight slump (like 2023–24) beats buying in a boom (2021).

10–12 years in ocean service, then another 15–25+ years on land. A one-trip box that's kept painted and dry can pass 30 years as a building or store. The killers are standing water on the roof and untreated scratches down to bare steel.

Usually on a tilt-bed (roll-off) truck that slides the box onto the ground — you need about 100 ft of straight clearance for a 40ft delivery and 60 ft for a 20ft. No crane needed on accessible sites; a crane day adds $800–2,500.

No. A container needs support only at its four corner castings: concrete blocks, poured piers or railroad ties work for storage. A full slab is only worth it for permitted buildings or point-loaded multi-box stacks. What matters is level — more than 1–2 inches of twist and the doors stop closing.

For temporary storage, often no — many counties allow 30–180 days unpermitted. As a permanent structure or dwelling, almost always yes: zoning approval plus building permit. Rules are county-by-county; HOAs are frequently stricter than the county.

An empty 20ft (≈4,850 lb) can be moved or rolled by EF2+ winds; loaded or anchored boxes are dramatically more stable. For wind-zone installs, anchor the corner castings to piers or ground anchors — an anchored container is among the most wind-resistant small structures you can put on a site.

"Container rain" is condensation on cold steel. Fixes, in escalating order: vents at both ends for airflow, desiccants for stored goods, insulation (closed-cell spray foam is the standard) for occupied boxes. Skip insulation in a lived-in box and the walls will literally drip.

All-in US figures: a DIY-heavy 20ft cabin $15,000–48,000; a turnkey 40ft one-bedroom $70,000–110,000; multi-container customs $150,000–300,000+. The four lines the '$30k home!' ads skip: foundation, delivery, utility hookups, and permits.

They win on speed (weeks, not months), price certainty from prefab builders, and durability. They don't win on cost per square foot vs stick framing once you pass ~2 containers — buy them for the speed, strength and look, not as a guaranteed discount.

The 40ft high cube is the standard answer: 300 sq ft, 8'10" internal height (so you keep 8ft ceilings after insulation), and the best price per square foot. One-trip condition is worth the premium — you're building a house on that steel.

50+ years is realistic for a one-trip box that's properly painted, sealed and kept dry — the same corten-family steel bridges are made of. The practical lifespan is set by maintenance: repaint scratches, keep the roof draining, control interior humidity.

Yes, but not usually with a standard mortgage. Routes: personal/RV-style loans for small builds, construction-to-perm loans where the home sits on a permanent foundation and meets code, and builder financing from larger prefab companies. Insurance follows the same logic — permanent foundation and code compliance unlock normal products.

No. They're broadly legal in rural and many suburban US zones, restricted in some cities and most HOAs. The gating factors: local zoning, state building codes (Texas, California and Florida are the most container-experienced), and whether your design gets an engineer's stamp.

A refrigerated container with a built-in cooling unit holding −20°F to +70°F, powered by 3-phase 440–460V. A working 20ft reefer costs $4,500–9,000 used; non-working 'insulated' units sell cheaper and make excellent cold-room shells.

Typically 5–10 kWh per hour of active cooling depending on setpoint and ambient — figure $15–35/day at US commercial rates. For static cold storage, a soft-start single-to-3-phase converter is a common site fix.

Cargo that loads by crane: machinery, glass, structural steel, logs. The roof is a removable tarpaulin over steel bows; dimensions otherwise match a standard box within an inch or two.

Oversized and overweight loads: vehicles, boats, transformers, industrial machines. It's a heavy steel deck with fixed or collapsible end walls — a 40ft flat rack carries up to 86,000 lb, more than any closed box.

The 11-character unit number (like MSCU 123456 7) is the BIC code: 4 letters (owner + 'U'), 6 digits, and a check digit computed from the rest. The separate 4-character code like 45G1 is the ISO size-type: first digit length, second height, letters for the type.