Washington Truck Weight Limits
Complete guide to commercial vehicle weight regulations in Washington, including axle limits, permit requirements, and seasonal restrictions.
Weight Limits
| Axle Type | Washington Limit | Federal Limit | Difference |
|---|---|---|---|
| Single Axle | 20,000 lbs | 20,000 lbs | 0 lbs |
| Tandem Axle | 34,000 lbs | 34,000 lbs | 0 lbs |
| Gross Vehicle Weight | 80,000 lbs | 80,000 lbs | 0 lbs |
| Steer Axle (min) | 12,000 lbs | 12,000 lbs | 0 lbs |
| Steer Axle (max) | 20,000 lbs | 20,000 lbs | 0 lbs |
Washington has source-verified table, spacing, route, permit, or vehicle-specific rules. The calculator applies verified base limits and implemented contexts, but exact special-case output still needs source-chart fixtures.
Washington has route-specific weight limits. Default calculation uses interstate/standard operation; select a route context for higher state-route limits.
Showing interstate route, standard operation.
Enforcement tolerance: 5% on gross weight.
Bridge Formula
Washington uses the standard Federal Bridge Formula to calculate maximum weight on groups of consecutive axles.
- W = Maximum weight (lbs)
- L = Distance between outer axles (ft)
- N = Number of axles in the group
Permissible Gross Loads in Washington
| Permissible Gross Loads for Vehicles in Washington | ||||||||
|---|---|---|---|---|---|---|---|---|
| Based on FederalBridge Formula: W = 500 × [LN/(N-1) + 12N + 36] | ||||||||
| Showing interstate route, standard operation | ||||||||
Distance (ft) L | 2 AXLES | 3 AXLES | 4 AXLES | 5 AXLES | 6 AXLES | 7 AXLES | 8 AXLES | 9 AXLES |
| 4 | 34,000 | — | — | — | — | — | — | — |
| 5 | 34,000 | — | — | — | — | — | — | — |
| 6 | 34,000 | — | — | — | — | — | — | — |
| 7 | 34,000 | — | — | — | — | — | — | — |
| 8 | 34,000 | 34,000 | — | — | — | — | — | — |
| 9 | 39,000 | 43,000 | — | — | — | — | — | — |
| 10 | 40,000 | 43,500 | — | — | — | — | — | — |
| 11 | 40,000 | 44,500 | — | — | — | — | — | — |
| 12 | 40,000 | 45,000 | 50,000 | — | — | — | — | — |
| 13 | 40,000 | 46,000 | 50,500 | — | — | — | — | — |
| 14 | 40,000 | 46,500 | 51,500 | — | — | — | — | 80,000 |
| 15 | 40,000 | 47,500 | 52,000 | — | — | — | — | 80,000 |
| 16 | 40,000 | 48,000 | 52,500 | 58,000 | — | — | — | 80,000 |
| 17 | 40,000 | 49,000 | 53,500 | 58,500 | — | — | — | 80,000 |
| 18 | 40,000 | 49,500 | 54,000 | 59,500 | — | — | — | 80,000 |
| 19 | 40,000 | 50,500 | 54,500 | 60,000 | — | — | — | 80,000 |
| 20 | 40,000 | 51,000 | 55,500 | 60,500 | 66,000 | — | — | 80,000 |
| 21 | 40,000 | 52,000 | 56,000 | 61,000 | 66,500 | — | — | 80,000 |
| 22 | 40,000 | 52,500 | 56,500 | 62,000 | 67,000 | — | — | 80,000 |
| 23 | 40,000 | 53,500 | 57,500 | 62,500 | 68,000 | — | — | 80,000 |
| 24 | 40,000 | 54,000 | 58,000 | 63,000 | 68,500 | 74,000 | — | 80,000 |
| 25 | 40,000 | 55,000 | 58,500 | 63,500 | 69,000 | 74,500 | 80,000 | 80,000 |
| 26 | 40,000 | 55,500 | 59,500 | 64,500 | 69,500 | 75,000 | 80,000 | 80,000 |
| 27 | 40,000 | 56,500 | 60,000 | 65,000 | 70,000 | 76,000 | 80,000 | 80,000 |
| 28 | 40,000 | 57,000 | 60,500 | 65,500 | 71,000 | 76,500 | 80,000 | 80,000 |
| 29 | 40,000 | 58,000 | 61,500 | 66,000 | 71,500 | 77,000 | 80,000 | 80,000 |
| 30 | 40,000 | 58,500 | 62,000 | 67,000 | 72,000 | 77,500 | 80,000 | 80,000 |
| 31 | 40,000 | 59,500 | 62,500 | 67,500 | 72,500 | 78,000 | 80,000 | 80,000 |
| 32 | 40,000 | 60,000 | 63,500 | 68,000 | 73,000 | 78,500 | 80,000 | 80,000 |
| 33 | 40,000 | 61,000 | 64,000 | 68,500 | 74,000 | 79,500 | 80,000 | 80,000 |
| 34 | 40,000 | 61,500 | 64,500 | 69,500 | 74,500 | 80,000 | 80,000 | 80,000 |
| 35 | 40,000 | 62,500 | 65,500 | 70,000 | 75,000 | 80,000 | 80,000 | 80,000 |
| 36 | 40,000 | 63,000 | 66,000 | 70,500 | 75,500 | 80,000 | 80,000 | 80,000 |
| 37 | 40,000 | 64,000 | 66,500 | 71,000 | 76,000 | 80,000 | 80,000 | 80,000 |
| 38 | 40,000 | 64,500 | 67,500 | 72,000 | 77,000 | 80,000 | 80,000 | 80,000 |
| 39 | 40,000 | 65,500 | 68,000 | 72,500 | 77,500 | 80,000 | 80,000 | 80,000 |
| 40 | 40,000 | 66,000 | 68,500 | 73,000 | 78,000 | 80,000 | 80,000 | 80,000 |
| 41 | 40,000 | 67,000 | 69,500 | 73,500 | 78,500 | 80,000 | 80,000 | 80,000 |
| 42 | 40,000 | 67,500 | 70,000 | 74,500 | 79,000 | 80,000 | 80,000 | 80,000 |
| 43 | 40,000 | 68,500 | 70,500 | 75,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 44 | 40,000 | 69,000 | 71,500 | 75,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 45 | 40,000 | 70,000 | 72,000 | 76,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 46 | 40,000 | 70,500 | 72,500 | 77,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 47 | 40,000 | 71,500 | 73,500 | 77,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 48 | 40,000 | 72,000 | 74,000 | 78,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 49 | 40,000 | 73,000 | 74,500 | 78,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 50 | 40,000 | 73,500 | 75,500 | 79,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 51 | 40,000 | 74,500 | 76,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 52 | 40,000 | 75,000 | 76,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 53 | 40,000 | 76,000 | 77,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 54 | 40,000 | 76,500 | 78,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 55 | 40,000 | 77,500 | 78,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 56 | 40,000 | 78,000 | 79,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 57 | 40,000 | 79,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 58 | 40,000 | 79,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 59 | 40,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 60 | 40,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
Values reflect FHWA policy of rounding down when calculated weights fall exactly halfway between 500-pound increments.
Washington GVW limit of 80,000 lbs differs from the federal interstate limit of 80,000 lbs.
Washington allows a 5% enforcement tolerance on gross weight.
Washington has source-verified table, spacing, route, permit, or vehicle-specific rules. The calculator applies verified base limits and implemented contexts, but exact special-case output still needs source-chart fixtures.
Washington has route-specific weight limits. Default calculation uses interstate/standard operation; select a route context for higher state-route limits.
Always verify current regulations with Washington DOT before making shipping decisions.
Permit Information
Requirements & Costs
- Overweight threshold
- 105,500 lbs
- Single trip permit
- $80
- Annual permit
- $800
- Processing time
- 24 hours
- Divisible loads
- Not permitted
- Online application
- Available
Required Documents
- Insurance
- Registration
Special Vehicle Provisions
interstate Vs Non Interstate
Interstate: 80,000 lbs GVW (federal). Non-interstate: up to 105,500 lbs GVW with sufficient axles (typically 7) under grandfather provisions for pre-1956 state routes.
logging
Log Tolerance Permits authorize weights exceeding legal weight formula for log trucks only. Route-specific, approved by city/county engineer. Annual permits expiring March 31.
agriculture
Farm implements exempt from axle limits up to 45,000 lbs GVW for short-distance highway moves. Agricultural permits for seasonal/route-specific hauling.
GVW: 45,000 lbs
permit Weights
Heavy haul permits can extend GVW up to 115,000 lbs on approved routes. Near ports, sealed shipping containers can move under permit at nearly 140,000 lbs GVW on industrial corridors.
Contact Information
Permit Office
Hours: Mon-Fri 8:00 AM - 5:00 PM PST
Official Website
Washington DOT WebsiteCalculate Your Weight Compliance
Use our interactive calculator to check if your truck configuration is compliant with Washington regulations.
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Get Expert ConsultationSource: Washington Revised Code Title 46 | Last Updated: 1/15/2025 | Effective: 1/1/2025
Always verify current regulations with official sources before making shipping decisions.