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Truck weight limit checker

By Fernandez · Updated October 2026

Check your scale ticket against federal limits before the next weigh station does.

Five-axle tractor-trailer, Interstate system

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lb
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  • Steer axle: 11,500 lb of 12,000 lb (common working limit (tire and state rules), not a federal cap)OK
  • Drive tandem: 33,500 lb of 34,000 lb (federal tandem limit)OK
  • Trailer tandem: 33,800 lb of 34,000 lb (federal tandem limit)OK
  • Gross: 78,800 lb of 80,000 lb (federal gross limit)OK

Result

Within federal limits

Bridge formula maximum

80,000 lb

Permit likely needed?

Not for weight

Federal limits from 23 U.S.C. 127; 23 CFR 658.17: 20,000 lb single axle, 34,000 lb tandem, 80,000 lb gross, and the bridge formula W = 500 (LN / (N - 1) + 12N + 36). States set their own limits off the Interstate and some grandfathered exceptions apply; state tables are not yet verified here, so check the state DOT.

We check weight on every load before you say yes, so you are not the one finding out at the scale.

Our dispatchers find and negotiate the loads; you approve each one and sign the rate con. 5% of gross for one truck with an MC 6 months or older, no setup fee.

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How the checker works

  • Steer axle against 12,000 pounds, a common working limit from tire ratings and state rules, labeled as an assumption.
  • Each tandem against the federal 34,000-pound limit.
  • Gross against the lower of 80,000 pounds and the bridge formula result for five axles and your distance.
  • Bridge formula: W = 500 (LN / (N - 1) + 12N + 36), rounded to the nearest 500 pounds.

Federal limits from 23 CFR 658.17 and 23 U.S.C. 127, checked October 2026. State-by-state tables are not yet verified here.

Worked example

Axle groupEXAMPLE weightLimitResult
Steer11,500 lb12,000 lb (working)OK
Drive tandem33,500 lb34,000 lbOK
Trailer tandem33,800 lb34,000 lbOK
Gross, 51 ft spread78,800 lb80,000 lbOK

If you are over

Sliding the fifth wheel moves weight between the steer and drive axles, and sliding the trailer tandems moves it between the drives and the trailer axles. If the gross is over, the load itself has to change or you need a permit. Never leave the shipper overweight hoping to avoid a scale.

Before you run in California, check emissions rules with the CARB Clean Truck Check compliance checker, and size a truck purchase with the how much truck can I afford calculator. Weight ratings also decide whether federal excise tax applies to a new truck; see the federal excise tax guide and the used semi truck checklist.

Weight mistakes that end in tickets

  • Trusting the bill of lading weight. Scale the load before you leave the shipper's area, and keep the ticket.
  • Forgetting fuel. A full set of tanks adds weight; a load that is legal empty-tanked may not be with full fuel.
  • Checking gross only. A truck can be legal on gross and still over on a tandem; check every axle group.
  • Assuming federal limits apply everywhere. State roads off the Interstate can have different limits and rules.
BOOKED

Weight checked before you say yes

We confirm weight and dimensions on every load. A dispatcher calls you back.

Get loads that fit my axles

Questions

What are the DOT weight limits per axle?
On the Interstate system, federal law sets 20,000 pounds on a single axle, 34,000 pounds on a tandem axle group and 80,000 pounds gross, subject to the bridge formula. These come from 23 U.S.C. 127 and 23 CFR 658.17. States set their own limits off the Interstate, and some have grandfathered exceptions.
What is the semi truck weight limit?
The federal gross limit on the Interstate is 80,000 pounds for a typical five-axle tractor-trailer, as long as the axle limits and the bridge formula are also met. Loads over that need an overweight permit from each state on the route, and permits come with their own routes and conditions.
What is the bridge formula?
It limits the weight on any group of axles based on how many axles there are and how far apart they are: W = 500 (LN / (N - 1) + 12N + 36), where L is the distance in feet and N the number of axles. Axles packed close together carry less weight than the same axles spread out.
What is the box truck weight limit?
A box truck's limit is its gross vehicle weight rating on the door label, along with the axle ratings. Many 26 ft box trucks are rated at or below 26,000 pounds, which keeps them under the commercial driver's license threshold. Overloading past the rating is unsafe and illegal whatever the road limit is.
Are steer axle limits federal?
There is no separate federal steer axle number in the same way as single and tandem limits. Many states and tire ratings work out to about 12,000 pounds on a steer axle, which the checker uses as a working figure and labels as such. Check your state's rule and your tire ratings.
What happens if my truck is overweight at a scale?
Fines are set by each state, not by federal law, and they usually rise with the pounds over. An officer can also order the load shifted or partly removed before you move on, which costs time and can mean a second trip. Checking your scale ticket against the limits before you leave the shipper avoids most of that.
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