Buying a shipping container is simpler than most people expect — but the details matter. The single most important thing to understand before you shop: there is no official global standard for grading shipping containers. "Cargo worthy," "wind and watertight," and "one-trip" are trade language, not certifications. Two dealers can apply the same label to visibly different containers and neither is breaking a rule. This guide covers what the grades actually mean, what the one legitimate external certification looks like, and how to inspect, buy, and take delivery without getting burned.
In this guide
Step 1
Choose the right size
10ft, 20ft, 40ft, high cube — a full breakdown of every standard size with interior dimensions and the right use case for each.
Size guide →Step 2
New vs used — which grade?
Container grades explained: one-trip, CWO, WWT, and AS-IS. What you actually get for each price point and when used is fine.
Grade guide →Most popular
20ft container guide
Complete specs, pricing, uses, and everything to inspect before you accept delivery of a 20ft container.
20ft guide →Most space
40ft container guide
Standard and high-cube 40ft containers: dimensions, pricing, delivery considerations, and who needs this size.
40ft guide →How buying a shipping container works
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01
Decide on size and grade
The two variables that drive price more than anything else. A one-trip 40ft costs roughly four times more than a used 20ft. Get clear on both before you start talking to suppliers.
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02
Get quotes from multiple suppliers
Container prices vary by location — depots in major port cities (LA, Houston, Savannah, Newark) tend to have the most inventory and competitive pricing. Getting three quotes is standard practice.
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03
Understand the delivery quote
Delivery is priced separately and varies significantly by distance from the depot. Confirm the delivery quote includes a tilt-bed truck drop (standard) and whether a crane or forklift is needed for placement.
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04
Inspect before or at delivery
For used containers, inspect in person at the depot if possible. At minimum, inspect the container before the delivery driver leaves — document any damage with photos immediately.
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05
Prepare your site
The delivery truck needs clear access — typically 60–70ft of straight clearance. The container needs a level surface: gravel pads, concrete piers, or a full slab depending on your use.
Container grades explained
The grade tells you the condition of the container — but remember: grades are seller-assigned. There is exactly one externally verified certification in this market: the CSC safety approval plate. Everything else is a description the seller applies themselves.
| Term | Who assigns it | Externally verified? | What it means in practice |
|---|---|---|---|
| One-trip / new | Seller, based on shipping records | No | Made one loaded ocean voyage from Asia. Essentially new condition — minor cosmetic marks only. The phrase "new" is a convenience; essentially every "new" container in North America has made one trip. |
| Cargo worthy (CW) | Seller, or a licensed surveyor if you pay for one | Only if a CSC survey was performed — the label alone is a claim | Seller represents it as structurally sound and suitable for international shipment. Typically 10–15 years old. Expect surface rust, dents, and repair patches on a sound box. |
| Wind & water tight (WWT) | Seller | No | No visible light inside with the doors closed — that is the field check the term describes. Not certified for shipping. Typically 14–18 years old off the fleet. Good for storage and most conversion projects. |
| AS-IS | Seller | No — by definition carries no guarantee | Sold as found. May have holes, structural issues, missing flooring, or pronounced damage. Legitimate uses exist (parts, heavy modification, non-critical storage). Never buy AS-IS sight unseen. |
| CSC safety approval plate | An organization authorized by a government administration — in the US, delegated by the Coast Guard Commandant under 49 CFR Part 450 | Yes — this is the real one | The only externally verified document on the container. Required for international transport. Contains manufacture date, load ratings, timber treatment used on the floor, and next examination date. |
⚠️ "Cargo worthy" is not the same as CSC certified
Sellers commonly state a container "would pass" a CSC survey. That is a claim, not a certification. If you need the certification — for international shipping, or because your building department requires it — you need to pay for an actual CSC survey. Most dealers add a few business days and a modest fee to perform one. The label alone is not enough.
A detail worth knowing about dent standards
Two container dealer guides describing the "cargo worthy" grade give different maximum dent depths — 2.5 inches in one, 1.5 inches in another. Both present these as though they were a standard. This is what an unregulated grading vocabulary looks like in practice. If a specific tolerance matters to your project, get it in writing from your seller.
What affects the price
Container prices are more dynamic than most buyers realize. The same 40ft one-trip container can cost $3,000 more or less depending on a handful of factors:
| Factor | Effect on price | Notes |
|---|---|---|
| Your distance from a depot | High | Every extra mile adds delivery cost. Inland locations pay significantly more than coastal. |
| Current inventory levels | High | Container supply tightens after major shipping disruptions, driving prices up 20–40%. |
| Size | High | 40ft containers cost roughly 50–80% more than 20ft in the same grade. |
| Grade / condition | High | One-trip vs WWT can be a $1,500–$3,000 gap on the same size. |
| High cube vs standard | Low–medium | High cube typically adds $300–$800 to the container price. |
| Color | None | Container color is cosmetic — don't pay extra for it. |
Delivery: what most buyers underestimate
Delivery typically adds $350–$2,000 to your purchase depending on distance from the nearest depot. The container price is often only 60–70% of what you actually spend — delivery and site prep make up the rest. Budget for the total, not just the container.
Site access requirements — measure before you choose a size
A tilt-bed (roll-off) truck needs clear straight-line clearance to slide the container off the back. These are the actual figures:
| Delivery method | Clearance required | Typical cost | Notes |
|---|---|---|---|
| Tilt-bed — 20ft container | 60ft+ straight-line, 14ft width, up to 20ft overhead | $350–$750 within 50 miles | The standard residential delivery method |
| Tilt-bed — 40ft container | 100ft+ straight-line, 14ft width, up to 20ft overhead | $350–$750 within 50 miles | Many residential lots with curved driveways or trees cannot accommodate this |
| Crane / hiab | Crane access and setup room | $300–$2,500+ added | Required when tilt-bed can't reach the placement site — over fences, into tight spaces |
| Flatbed (long haul) | You provide crane or forklift on site | Often cheaper per mile than tilt-bed | Used beyond 200 miles; container doesn't come off the truck itself |
A cost-saving detail worth asking about
A standard tilt-bed truck can carry two 20ft containers in a single trip. If you need two, ask for a consolidated delivery rather than booking two runs. The same 100ft of clearance covers one 40ft or two 20ft units — and you pay one delivery fee instead of two.
Ground preparation
A shipping container weighs 4,900–8,600 lbs empty. It needs a stable, level surface — not bare soil that will shift seasonally. Uneven settling racks the frame and misaligns the doors — the most common avoidable damage in container ownership.
| Foundation option | Typical cost | Best for |
|---|---|---|
| Bare level ground | $0 | Short-term placement on firm, well-drained ground only |
| Gravel base | $300–$800 | Long-term storage; provides drainage and a stable bearing surface |
| Concrete pads or piers | $1,500–$3,000 | Permanent placement; required for most habitable conversions |
What to inspect at delivery
For used containers, inspect these points before signing the delivery receipt:
- Roof: walk it if you can safely. Dents that hold water lead to rust through.
- Floor: jump on it and look for soft spots. Container floors are hardwood — they should feel solid everywhere.
- Doors: open and close both doors. They should move freely, seal fully, and lock properly. Door gaskets should be intact and supple, not cracked or missing.
- Interior walls and ceiling: look for holes (light from outside), heavy rust, or signs of previous cargo spills.
- Undercarriage: check the steel cross-members underneath for rust-through. Surface rust is normal; perforations are not.
- Smell: take a sniff inside before accepting. Certain chemical cargos leave a permanent odor that can't be fully removed.
Document everything before the driver leaves
Once you sign the delivery receipt, you own the container in the condition it arrived. Take dated photos of every side and the interior before signing. If there's damage you didn't agree to, note it on the delivery paperwork before the driver leaves.
The Floor — What Every Buyer Should Know
Container floors are typically massive boards of tropical hardwood — commonly Keruing or Apitong — pressure-treated with pesticides and fungicides to survive years in humid, pest-exposed environments and to satisfy international phytosanitary requirements. This is not a minor detail for anyone using a container as a habitable space.
| Treatment category | Compounds found in industry sources |
|---|---|
| Modern proprietary treatments | Basileum, Talileum-400, Radaleum — names most often found on data plates |
| Insecticides | Cypermethrin and chlorpyrifos in modern containers; historically aldrin and dieldrin |
| Wood preservatives | Historically chromated copper arsenate (CCA) — restricted for residential use in the US in 2003; manufacturers moved to ACQ, copper azole, borates, and micronized copper |
| Fumigants | Methyl bromide and sulfuryl fluoride have been used; heat treatment at 56°C for 30 minutes is the alternative phytosanitary method |
The timber treatment information is on the CSC plate — read it before you buy, not after. For storage or non-occupied use, this is not a concern. For any occupied conversion, choose one of three paths: seal the existing floor with a non-breathable barrier such as a solvent-free epoxy, cover it with a non-breathable underlayment and finished flooring, or remove and replace the floor entirely.
⚠️ If you sand a container floor, use P100 respiratory protection
Sanding a treated container floor aerosolizes the treatment chemicals along with whatever the wood absorbed from previous cargo. Trade guidance calls for P100 protection — that is the correct level, not an abundance of caution. Also: never pressure wash the interior. High-pressure water forces moisture into seams where it cannot dry, causing rot.
Questions to Ask Every Seller
| # | Question | Why it matters |
|---|---|---|
| 1 | Can I have the container ID number? | The single most effective anti-fraud step. A legitimate seller has a specific container in a specific yard and can give you its ISO 6346 ID immediately. Refusal is a documented red flag. |
| 2 | Do you own this container, or are you a broker sourcing it from a depot? | Brokers aren't a problem but you should know — it affects your leverage if something goes wrong. |
| 3 | Can I inspect before paying, or is delivery pay-on-arrival? | The best protection against grade misrepresentation. Insist on one of these. |
| 4 | What is the all-in price including delivery, taxes, and any fees? | Gets the total number on the table before you're committed. Hidden fees are the second most common complaint. |
| 5 | What exactly does your grade guarantee cover, and is it in writing? | Forces the seller to define their terms specifically rather than rely on undefined grade language. |
| 6 | What does the CSC plate say about timber treatment? | Relevant for any occupied conversion. The answer is on the plate — ask what it says before buying. |
| 7 | What clearance does your truck need at my site? | Prevents the expensive surprise of a crane being needed after you've committed to the purchase. |
| 8 | If it arrives not matching the description, what is the remedy? | Establishes the dispute path before you need it. A seller who can't answer this is a yellow flag. |
Common Container Buying Mistakes
| Mistake | Consequence |
|---|---|
| Treating grade names as certifications | There is no official global grading standard. Grades are seller-assigned trade language, and dealers publish conflicting definitions of the same grade. |
| Assuming "cargo worthy" means CSC certified | It means the seller believes it would pass a survey. If you need certification, buy the survey. |
| Buying a standard-height container for a conversion | About 7'10" interior height becomes very tight once floor and ceiling assemblies go in, and may fall below code minimums for habitable space. |
| Not measuring site access before choosing size | A 40ft tilt-bed delivery commonly needs around 100ft of straight-line clearance. Many residential lots cannot take it. |
| Forgetting overhead clearance | The tilt bed rises high behind the cab. Power lines and tree limbs stop deliveries on arrival. You need 16ft of overhead clearance. |
| Budgeting only the container price | Delivery and site prep frequently add 30–40% or more to the total. |
| Paying by wire transfer | Essentially irreversible. Credit cards carry chargeback rights — use them where possible. |
| Not asking for the container ID | It is the simplest fraud check available and a documented red flag when refused. |
| Ignoring the floor in a conversion | The wood is pesticide-treated by design and may have absorbed cargo spills. Seal it or replace it for occupied space. |
| Setting a container on unprepared ground | Uneven settling racks the frame and misaligns the doors — the most common avoidable damage. |
| Buying AS-IS sight unseen | By definition there is no condition guarantee. Holes, missing floors, and structural damage are all in scope. |
Which Container for Which Use
| Your use | Grade | Size | Notes |
|---|---|---|---|
| Backyard or job-site storage | Wind & water tight | 20ft | The value sweet spot. Appearance is irrelevant; watertightness is everything. |
| Workshop or hobby space | Cargo worthy or WWT | 20ft or 40ft High Cube | High Cube if you will be standing in it for long stretches. |
| Office, retail, or customer-facing conversion | One-trip | 40ft High Cube | Appearance matters and you are paying for finish work regardless. Start with a good box. |
| Habitable structure | One-trip | High Cube | Uncut corner castings keep you eligible for simplified structural design under the building code. Also your best shot at specifying untreated flooring. |
| International shipping | Cargo worthy with a current CSC survey | As needed | The label is not enough. Pay for the survey. |
| Heavy modification where the box is mostly a frame | Cargo worthy | As needed | No reason to pay a one-trip premium for panels you are cutting out. |
| Parts, scrap, or non-critical shed | AS-IS | Any | Inspect in person. Never buy this grade sight unseen. |
Quick Reference
| Item | Figure |
|---|---|
| 20ft floor area | ~150 sq ft |
| 40ft floor area | ~320 sq ft |
| Standard interior height | ~7'10" |
| High Cube interior height | ~8'10" |
| Tilt-bed clearance — 20ft | 60ft+ straight-line |
| Tilt-bed clearance — 40ft | 100ft+ straight-line |
| Width clearance | ~12ft |
| Overhead clearance | ~16ft |
| Empty container weight | ~4,900–8,600 lbs depending on size |
| Local delivery cost (within 50 miles) | $350–$750 typically |
| Gravel base prep | $300–$800 |
| Concrete pad prep | $1,500–$3,000 |
| CSC initial validity | 5 years from manufacture |
| CSC reinspection interval | Not to exceed 30 months |
| Fraud reporting | ic3.gov · reportfraud.ftc.gov · BBB |
Going to inspect a container?
Download our free 34-point inspection checklist — covers structural assessment, rust-through detection, Bondo test, door and seal inspection, floor condition, and cargo history verification.