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Haul Math

California Truck Weight and Size Limits

Legal limits for a truck in California without a permit: Interstate axle and gross weights, height, width, and semitrailer length, each with its official source.

California limits at a glance

California truck size and weight limits with sources
LimitCaliforniaSource
Interstate gross weight80,000 lb23 CFR 658.17, Weight (eCFR)
Interstate single axle20,000 lb23 CFR 658.17, Weight (eCFR)
Interstate tandem axle34,000 lb23 CFR 658.17, Weight (eCFR)
Width (National Network)102 in23 CFR 658.15, Width (eCFR)
Height14 ft (vehicles over 13 ft 6 in only on highways the operator deems safe)Cal. Veh. Code § 35250
Semitrailer length48 ft; up to 53 ft on the Interstate, qualifying federal-aid highways, and identified routes if the rearmost axle is 40 ft or less from the kingpin (38 ft for a single axle)Cal. Veh. Code § 35401.5
Grandfathered semitrailer length48 ft23 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").

Bridge formula check with California 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 California's Interstate limits.

Axle spacings

Center of one axle to the center of the next, in feet. Axle 1 is the steer axle. 4 ft 6 in = 4.5.

Axle weights (optional)

From your scale ticket. Leave all blank to see the limits only.

Your result

Enter your axle spacings and tap "Check bridge formula". A 5-axle tractor-trailer is filled in.

Open the full bridge formula calculator →

California limits off the Interstate

FHWA's summary of California 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. / Alternative method of computation: 18,000 lbs. / Alternative method of computation, limit on steering axle: 12,500 lbs.
Tandem axle
34,000 lbs. / Alternative method of computation: 33,600 lbs.
Tridem axle
Not defined in statute but subject to provisions
Gross weight
80,000 lbs. / Alternative method of computation: 76,800 lbs.

Where California allows more than federal limits

Height, width, and length

Over these limits you need a permit. California oversize/overweight permits (916-322-1297).

California compared with neighboring states

Interstate weight limits, height, and semitrailer length. "Pending" means not yet verified.
StateGrossSingleTandemHeightSemitrailer
California80,000 lb20,000 lb34,000 lb14 ft48 ft
Arizona80,000 lb20,000 lb34,000 lb13 ft 6 in57 ft 6 in
Nevada80,000 lb20,000 lb34,000 lb14 ftPending
Oregon80,000 lb20,000 lb34,000 lb14 ftPending

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: California · 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: Cal. Veh. Code § 35401.5 · Last verified Sep 28, 2026

Source: Cal. Veh. Code § 35250 · 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 California before you run a load near the limits. Page data last verified Sep 28, 2026.

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