Tri Axle Dump Truck Capacity FAQs

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Do you need a CDL for a tandem dump truck?

A tandem dump truck usually needs a Class B CDL, because 49 CFR 383.91 covers any single truck rated at 26,001 lb GVWR or more, and tandems typically carry 52,000 to 66,000 lb ratings. States issue CDLs and may grant narrow exemptions, such as for some farm vehicles, so the state DMV confirms.

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How do you calculate dump truck capacity?

Dump truck capacity is the smaller of two limits, body volume and legal payload. Volume is inside length times width times height in feet, divided by 27 for cubic yards. Payload is legal gross weight, set by GVWR and state or Bridge Formula limits, minus empty weight, divided by material weight per cubic yard.

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How many cubic yards is a 20-ton dump truck?

A 20-ton load equals roughly 13 to 18 cubic yards of dry fill dirt, since a cubic yard of dry fill weighs about 1.1 to 1.5 tons. The same 20 tons is about 14 cubic yards of dry 1/4 to 2 inch gravel. Moisture adds weight, and body volume can cap the load first.

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What is the typical capacity of a tandem axle dump truck?

A tandem axle dump truck typically hauls 10 to 14 cubic yards or 12 to 18 tons, per HomeGuide's 2026 guide. Heavy material hits the weight limit before the body fills, so a 12-yard truck hauling wet clay may legally carry only 8 to 9 yards. Limits vary by truck rating and state law.

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What is the difference between a tandem and a tridem axle?

A tandem is two consecutive axles more than 40 and up to 96 inches apart, capped at 34,000 lb on the Interstate. A tridem is three closely spaced axles with no fixed federal cap, so the Bridge Formula sets its limit. FHWA's example tridem spread 9 feet gets 42,500 lb, and states vary.

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What is the maximum weight for a tri-axle dump truck?

A tri-axle dump truck has no single federal maximum, because axle spacing sets it. On the Interstate, the Bridge Formula applies under an 80,000 lb cap, and FHWA's example four-axle straight truck with a 23-foot axle spread tops out at 57,500 lb. States set their own limits elsewhere, often 60,000 to 73,000 lb.

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How many tons are in a tri-axle dump truck?

Tri-axle dump truck payload is the legal gross weight minus the empty truck, which HomeGuide puts at 32,000 to 36,000 pounds. HomeGuide lists typical loads of 18 to 25 tons, but a truck registered for 66,000 pounds gross, for example, carries only about 15 to 17 tons. State weight laws set the limit.

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How many yards of dirt can a tri-axle dump truck hold?

A tri-axle dump truck typically holds about 15 to 16 cubic yards of dirt, though HomeGuide lists 12 to 16 by body size. Weight often limits the load first, so wet clay at about 1.4 tons per yard reaches the legal payload with fewer yards aboard. State weight laws set the real limit.

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