Axle Load & Bridge Formula Calculator
Check per-axle legal weights and US Federal Bridge Formula compliance across US states and Canadian provinces — free, no login.
What It Does
The Axle Load & Bridge Formula Calculator checks a vehicle configuration against per-axle legal weight limits and the US Federal Bridge Formula. It covers all 50 US states, DC, and every Canadian province and territory. It is a free public tool — no account required.
Using the Calculator
1. Open roadscope.app/tools/axle-load-calculator (also linked from the site Tools menu)
2. Build your axle configuration: add each axle or axle group (steer, single, tandem, tridem, quad+) with its weight, spacing, and tire type
3. Select the jurisdictions to check — one or several US states and Canadian provinces
4. Review the results per jurisdiction: legal / non-compliant status per axle group, gross weight check, and Bridge Formula compliance
Interpreting Results
Each jurisdiction card shows which axle groups exceed the legal limit, the overall verdict, and whether an overweight permit would be required. You can print the results or export them for your permit file.
Rule Data & Verification
Each jurisdiction indicates whether its rule data has been verified against official sources and what route classes the values apply to. Lower limits can apply on other route classes or during seasonal restrictions — always confirm against the permit office for the final application.