Iowa Truck Weight Limits
Iowa keeps the federal 80,000 on the Interstate, but a 7-axle commercial rig can legally gross up to 96,000 off the Interstate on the right axle spacing (Iowa Code 321.463). Single axle 20,000, tandem 34,000. Fines are steep and uncapped: run more than 20,000 pounds heavy and it is $2,200 plus a dime a pound. Gross-weight tickets are half the axle-schedule rate.
How much a truck can weigh in Iowa
Iowa keeps the federal 80,000 on the Interstate, but a 7-axle commercial rig can legally gross up to 96,000 off the Interstate on the right axle spacing (Iowa Code 321.463). Single axle 20,000, tandem 34,000. Fines are steep and uncapped: run more than 20,000 pounds heavy and it is $2,200 plus a dime a pound. Gross-weight tickets are half the axle-schedule rate.
Axles, off-Interstate, and permits
- Off the Interstate: Up to 96,000 lb for a 7-axle commercial rig on non-interstate highways by bridge-formula spacing (Iowa Code 321.463(6)(c)); 80,000 lb for a standard 5-axle; 86,000 lb for a 5-axle livestock load
- Single axle: 20,000 lb
- Tandem axle: 34,000 lb
- With a permit: 96,000 lb legal for a 7-axle commercial vehicle off the Interstate (no permit); indivisible-load and superload permits (Iowa Code ch. 321E) authorize more case-by-case
- Off-Interstate, Iowa's noninterstate CMV table lets a 6-axle rig reach 90,000 and a 7-axle rig 96,000 by axle spacing alone with no permit, while the Interstate holds at 80,000. Livestock 5-axle 86,000. Heavier or indivisible moves need a 321E permit. The axle fine schedule has no ceiling.
Posted bridge and road limits
Iowa posts bridges and roads under Iowa Code 321.471-321.474 with MUTCD 'WEIGHT LIMIT __ TONS' signs (short tons; a 5-ton sign = 10,000 lb). The posted limit overrides the legal maximum - 321.463(9) makes you obey the sign even when running legal weight. Cross a posted bridge over its limit and it is a separate violation, with liability for any damage.
What running heavy costs
Scheduled fine by pounds over the axle/tandem/group limit (Iowa Code 321.463(11)): up to 1,000 = $12; 1,001-2,000 = $22; 2,001-3,000 = $155; 3,001-4,000 = $240; 4,001-5,000 = $375; 5,001-6,000 = $585; 6,001-7,000 = $850; then $100 more per 1,000 up to $2,200 at 19,001-20,000; over 20,000 = $2,200 plus 10 cents/lb over 20,000. Gross-weight violations are billed at one-half the axle schedule. No cap, and it is a simple misdemeanor.
Iowa Truck Weight Limit FAQ
What is the truck weight limit in Iowa?
How much can a truck weigh with a permit in Iowa?
What is the overweight fine in Iowa?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://www.legis.iowa.gov/docs/code/321.463.pdf ; https://law.justia.com/codes/iowa/title-viii/chapter-321/section-321-463/. See our Terms & Disclaimer.
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