Will it fit: container sizing tool and door openings

Measured against door openings, not interiors, and assuming the load goes in upright on its own base. Availability is a separate question: a 45ft wide box is common on the Caribbean and Latin America services out of Miami and rare elsewhere. Send us the numbers and we will tell you what is actually callable on your lane.

On weight, the number that binds you is the road one, not the box's plate. A container may be rated to carry 56,000lb or more at sea, while a US road move is capped at 80,000lb for the whole combination, so once a tractor, a chassis and the container's own empty weight are paid for, the legal cargo is commonly in the low forties of thousands of pounds. Rows marked carrier published are the shipping line's own highway figures. Rows marked our arithmetic are 80,000lb less a tractor, a chassis and the tare, and a lighter day cab or a lightweight chassis buys some of it back.

The road figures here are the published ones, not arithmetic on a guessed tractor: the Florida road table and the ocean carriers' OCEMA guideline for the dry boxes, Crowley's equipment specifications for the 45s and the reefers. A 40 ft dry box takes 44,000 lb of cargo on a standard chassis, a 45 about 41,700, a 40 ft reefer about 40,000, and a 20 stops at 38,000 unless it rides a tri-axle. Over those numbers the load is a permitted overweight move, not an illegal one.

The 20ft figures are published rather than calculated, and that is deliberate. A 20 is not stopped by gross weight: loaded to 38,000lb the whole combination weighs about 66,000, well under the limit. What stops it is the bridge formula, which cares how tightly weight is packed into a length of road, and a tractor with a 20ft chassis puts four axles into about 22 feet. Subtracting your way to a 20ft answer returns roughly 52,000lb and would be illegal by a wide margin, so we use carriers own published numbers instead. A tri-axle takes a 20 to about 44,000lb. If your 20 is heavy, call before it is loaded rather than after.

There is an escape hatch for the longer boxes. Florida issues a sealed container permit allowing up to 100,000lb gross on named routes, provided the container keeps its original unbroken seal throughout, and for freight a few thousand pounds over it often beats a second container. Check the conditions first: five load bearing axles minimum and an outer bridge of 51 feet or more. A tractor and a 20ft chassis measure around 37 to 40 feet, so a 20 does not reach it on ordinary equipment. This is a 40 and 45 instrument. One ceiling the permit prose never mentions: the chassis has its own rating, and a pool extendable is commonly rated to carry about 58,200lb of loaded container, so on a permitted 45 the chassis can stop you at roughly 47,600lb of cargo whatever the permit allows.