Wisconsin Truck Weight and Size Limits
Legal limits for a truck in Wisconsin without a permit: Interstate axle and gross weights, height, width, and semitrailer length, each with its official source.
Wisconsin limits at a glance
| Limit | Wisconsin | Source |
|---|---|---|
| Interstate gross weight | 80,000 lb | 23 CFR 658.17, Weight (eCFR) |
| Interstate single axle | 20,000 lb | 23 CFR 658.17, Weight (eCFR) |
| Interstate tandem axle | 34,000 lb | 23 CFR 658.17, Weight (eCFR) |
| Width (National Network) | 102 in | 23 CFR 658.15, Width (eCFR) |
| Height | 13 ft 6 in | Wis. Stat. § 348.06(1) |
| Semitrailer length | 53 ft if the kingpin to axle distance is 43 ft or less, on designated highways | Wis. Stat. § 348.07(2)(gr), (gv) |
| Grandfathered semitrailer length | 48 ft | 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) |
Interstate weight limits
Federal law sets the Interstate limits at 20,000 lb on a single axle, 34,000 lb on a tandem, and 80,000 lb gross, with the bridge formula on every axle group (23 CFR 658.17). States may keep higher limits they had before the federal limits took effect ("grandfather rights").
Grandfathered limits on I-39 (I-94 near Portage to WI-29 south of Wausau) that vary by commodity.
Bridge formula check with Wisconsin limits
A 5-axle tractor-trailer is filled in. Change the spacings and weights to match your rig; the limits for single axles, tandems, and gross are Wisconsin's Interstate limits.
Your result
Wisconsin limits off the Interstate
FHWA's summary of Wisconsin law for trucks in regular operation (no permit), including non-Interstate highways. It reflects state law as of October 1, 2012; check the state for later changes.
- Single axle
- 20,000 lbs.
- Tandem axle
- 34,000 lbs.
- Tridem axle
- Not defined in statute, subject to State's bridge formula
- Gross weight
- State bridge formula / 80,000 lbs. (5-axle or more)
- Other
- Steering axle 20,000 lbs. Gross weight of any one wheel or multiple wheels supporting one end of an axle may not exceed 11,000 lbs.
Where Wisconsin allows more than federal limits
- Wisconsin State statute allows for several axle and GVW exemptions for various types of vehicles and commodities.
- Wisconsin State statute allows for several tolerances for axle weights and/or GVW.
Height, width, and length
- Width: 102 inches. States may not set a width limit of more or less than 102 inches on the National Network (23 CFR 658.15(a)). Permits can allow wider loads.
- Height: 13 ft 6 in. There is no federal height limit; each state sets its own.
- Semitrailer length: 53 ft if the kingpin to axle distance is 43 ft or less, on designated highways
- Grandfathered semitrailer length: 48 ft. The minimum semitrailer length the state must allow in a tractor-semitrailer combination on the National Network, based on lengths legal in the state on December 1, 1982. Federal law also requires at least 48 ft (23 CFR 658.13(b)(1)). Semitrailers up to 53 ft may operate without a permit with a kingpin-to-rear-axle distance of 41 ft, measured to the center of the rear tandem.
Over these limits you need a permit. Wisconsin oversize/overweight permits (608-266-7320).
Wisconsin compared with neighboring states
| State | Gross | Single | Tandem | Height | Semitrailer |
|---|---|---|---|---|---|
| Wisconsin | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 53 ft if the kingpin to axle distance … |
| Illinois | 80,000 lb | 20,000 lb | 34,000 lb | Pending | Pending |
| Iowa | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 53 ft in a truck tractor-semitrailer c… |
| Michigan | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 50 ft |
| Minnesota | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 48 ft |
Sources
Source: 23 CFR 658.17, Weight (eCFR) · Last verified Sep 28, 2026
Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix A: Wisconsin · Effective Oct 1, 2012 · Last verified Sep 28, 2026
Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix B: Summary of State Exceptions to Federal Truck Weight Limits · Effective Oct 1, 2012 · Last verified Sep 28, 2026
Source: 23 CFR 658.15, Width (eCFR) · Last verified Sep 28, 2026
Source: 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) · Last verified Sep 28, 2026
Source: Wis. Stat. § 348.07(2)(gr), (gv) · Last verified Sep 28, 2026
Source: FHWA, Oversize/Overweight Load Permits: State permit contacts · Last verified Sep 28, 2026
Limits change, and cities, counties, and posted bridges can set lower ones. Check with Wisconsin before you run a load near the limits. Page data last verified Sep 28, 2026.