REFERENCE
Container Sizes & Capacity
Quick reference for standard ocean shipping containers — dimensions, payload, and use cases.
STANDARD EQUIPMENT
Standard ocean containers
The three most common containers in international ocean freight. Use these for general cargo, mixed loads, and most agricultural exports.
| Container | Internal Dims (L × W × H) | Tare Weight | Max Payload | Max Gross | Max Volume |
|---|---|---|---|---|---|
| 20' Standard | 5.9m × 2.35m × 2.39m | 2,300 kg / 5,071 lb | 28,180 kg / 62,128 lb | 30,480 kg / 67,200 lb | 33.2 m³ / 1,172 ft³ |
| 40' Standard | 12.03m × 2.35m × 2.39m | 3,750 kg / 8,267 lb | 28,750 kg / 63,382 lb | 32,500 kg / 71,650 lb | 67.7 m³ / 2,389 ft³ |
| 40' High Cube | 12.03m × 2.35m × 2.70m | 3,940 kg / 8,686 lb | 28,560 kg / 62,964 lb | 32,500 kg / 71,650 lb | 76.4 m³ / 2,697 ft³ |
SPECIALTY EQUIPMENT
Reefer, flat rack, open top, and tank containers
Specialty equipment for cargo that doesn't fit standard containers — temperature-controlled, oversized, over-height, or bulk liquid.
| Container | Internal Dims | Tare Weight | Max Payload | Max Gross | Use Case |
|---|---|---|---|---|---|
| 20' Reefer | 5.45m × 2.29m × 2.27m | 3,080 kg / 6,790 lb | 27,400 kg / 60,406 lb | 30,480 kg / 67,196 lb | Temperature-controlled cargo |
| 40' Reefer | 11.56m × 2.29m × 2.51m | 4,800 kg / 10,582 lb | 27,700 kg / 61,067 lb | 32,500 kg / 71,650 lb | Cold chain, dairy, perishables |
| 40' Flat Rack | 12.13m × 2.40m | 5,700 kg / 12,566 lb | 39,300 kg / 86,641 lb | 45,000 kg / 99,208 lb | Oversized, heavy machinery |
| 40' Open Top | 12.03m × 2.35m × 2.39m | 3,860 kg / 8,510 lb | 26,640 kg / 58,732 lb | 30,500 kg / 67,242 lb | Over-height cargo |
| 20' ISO Tank | 24,000 L capacity | 4,200 kg / 9,259 lb | 26,000 kg / 57,320 lb | 30,200 kg / 66,579 lb | Bulk liquids, hazmat |
ROAD WEIGHT LIMITS
What you can actually move on the road varies.
A container's structural payload is what it can hold safely. What it can carry on US roads is a different number — and that number depends on the route.
The US baseline
Federal law caps the total weight of a truck, chassis, container, and cargo at 80,000 lbs on US Interstates. After accounting for tractor weight (typically 17,000–19,000 lbs), chassis weight (7,000–10,000 lbs), and the container itself, the practical cargo limit usually works out to 44,000–44,500 lbs in a standard 40' container. Most major carriers — including OOCL and ACL — publish this as their standard payload guideline.
Where you can go higher
Triaxle chassis (20' containers only): Carries up to 44,000 lbs of cargo. 20' containers can run on either tandem or triaxle chassis — triaxle distributes weight across three axles, allowing heavier dense cargo. 40' containers run on tandem chassis only.
Southeast state permits: With overweight permits, 40' container payloads can reach 48,000 lbs in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia.
Port of NY/NJ heavy haul corridors: With specialized equipment (quad-axle tractors, triaxle chassis) and special permits, gross vehicle weight increases from 80,000 to 90,000 lbs — allowing 40' container payloads up to 55,000 lbs. Available routes to NY, NJ, PA, DE. New England slightly lower (~47,000 lbs).
Canada (where applicable): Canadian road rules allow higher per-container loads than US standard — 55,000 lbs in a 40' and 48,000 lbs in a 20' without triaxle surcharge. Spring thaw restrictions apply March–May.
Michigan: Under grandfather provisions, allows up to 164,000 lbs gross with properly-spaced 11-axle configurations on specific routes. Few other states match this.
Reefer specifics
Refrigerated containers add weight from the refrigeration unit and require fuel for the gen-set, which eats into available cargo payload. A 40' reefer typically maxes around 41,000–41,500 lbs of cargo even on a standard chassis. Carriers like OOCL flag reefers above 41,500 lbs as needing special handling.
What this means for your shipment
There is no single "US road weight limit." What you can actually move depends on your origin port, your destination state, your chassis options, your routing, and whether overweight permits make sense for the lane. Conveyco coordinates the equipment, routing, and permits to optimize cargo weight on every shipment. We'll tell you exactly what's possible for your specific lane before you book — including whether splitting cargo across multiple containers or using triaxle equipment will save money.
Reference data from OOCL Operational Restrictions, ACL Payload Guidelines, and US Federal Highway Administration. Specific limits change by state and route — confirm with carrier before booking.
GUIDANCE
Picking the right container for your cargo
Payload vs Volume
Heavy, dense cargo (steel, minerals, machinery) maxes out the weight limit before filling the container. For these, 20' Standard is often most cost-effective. Light, bulky cargo (insulation, foam, packaged consumer goods) fills the space before hitting weight limits. For these, 40' High Cube gives you the most usable volume.
When You Need a Reefer
Anything requiring temperature control — dairy, fresh food, frozen goods, chemicals with temperature sensitivity, pharmaceuticals. Reefers maintain temperatures from -25°C to +25°C and require pre-trip inspection (PTI) and continuous monitoring.
When You Need Specialty Equipment
Flat rack: Cargo exceeding container width or floor strength — heavy machinery, oversized industrial equipment. Open top: Cargo exceeding container height — pipes, large pieces of equipment, cargo loaded by crane. Tank: Bulk liquids — chemicals, food-grade liquids, vegetable oils.
Working with Conveyco
Not every shipment fits neatly into one container type. We help customers choose the right equipment by working through cargo dimensions, weight, route, and budget. Sometimes splitting cargo across multiple containers costs less than one specialty container. We'll work the math with you.
Tare weights and payloads listed are typical industry values for current-spec equipment. Actual values vary by manufacturer and equipment provider. Always confirm exact specs with your container provider before booking.
Not sure what you need?
Tell us about your cargo and we'll recommend the right equipment.