Weight check
Use the numbers from your truck: the sticker in the driver's door jamb, your owner's manual, and the labels on your hitch and ball mount. Leave a box empty if you don't know it.
EXAMPLE: made-up round numbers to show how the check works. They are not from any real truck. Put in your own numbers.
Your truck
Your hitch
Your trailer
Your results
Close means within 10% of the limit. Over means past it. We estimate your empty truck weight as GVWR minus payload, so a truck-scale ticket is always better than math.
Federal rules (U.S. DOT / FMCSA)
These federal rules are mainly for business towing. Turn on Business above and we'll show which ones your numbers trigger.
| Rule | When it applies | Source |
|---|---|---|
| USDOT number | Business (interstate commerce) with a truck, trailer, or combination whose weight rating or actual weight is 10,001 lb or more. Some states also require one for in-state business; FMCSA lists Alabama as one of them. | FMCSA: Do I need a USDOT number? |
| Medical card (DOT physical) | Drivers of a commercial motor vehicle in interstate commerce, which includes 10,001 lb+ business combinations, need a medical examiner's certificate. | 49 CFR 391.41 · FMCSA medical page · CMV definition: 49 CFR 390.5 |
| CDL Class A | Combination with GCWR 26,001 lb or more when the towed unit is over 10,000 lb. | FMCSA: CDL drivers · 49 CFR 383.5 |
| CDL Class B | Single vehicle with GVWR 26,001 lb or more, or one towing a unit of 10,000 lb or less. | FMCSA: CDL drivers |
| CDL Class C | Smaller vehicles that carry 16+ people (driver included) or haul placarded hazardous materials. | FMCSA: CDL drivers |
| Personal / recreational exception | Federal CDL rules cover commerce. Towing your own camper or moving your own things, not for pay or a business, is generally outside them. FMCSA says states may still require a special license for big RVs, and states vary (see your state below). | FMCSA guidance on RVs · FMCSA FAQ: non-business · 49 CFR 390.3(f) |
| Hazmat | Hauling hazardous materials in amounts that need placards: a CDL with an H endorsement is required at any size, and some loads also need a hazmat safety permit. | FMCSA: CDL endorsements · 49 CFR 385 Subpart E |
Federal sources checked October 24, 2026. FMCSA uses the weight rating or the actual weight, whichever is higher.
State towing laws
Pick a state to see its rules. Each line links to where we found it and says how sure we are.
Official text we read it on the state's own site · Compilation from a published list (check before you rely on it) · Not verified we couldn't confirm it
| Rule | What we found | Source |
|---|
Trip mode: crossing several states?
Tick every state on your route. We'll show the strictest rule so one plan works everywhere.
Tire pressure
Type the pressures from your tire placard (driver's door jamb) and your trailer tires' sidewall. We don't fill in PSI for you, because the right number depends on your exact tires and load.
- Check cold, before you drive, with a good gauge. Driving warms tires and raises the reading. Don't let air out of hot tires.
- Truck tires: use the door placard (or your manual's towing/loaded number). The sidewall number on a truck tire is a maximum, not the target.
- Trailer tires: trailer-tire maker Carlisle says to "maintain air pressure at the maximum PSI recommended on the tire sidewall" and check when tires are cold (Carlisle trailer tire FAQ, checked October 24, 2026). Other tire makers may say something different, so check the tire maker for your tires.
- Never go above the sidewall max.
Pre-trip checklist
Tick each one as you go. Your ticks stay on this device only.
The reminder is a calendar file (.ics) made on your device. Open it to add it to your phone's calendar. Nothing is sent to us.
Trip plan
Where to stay
Links to the real booking sites. No sign-ups here, and we don't list prices, because they change.
State park links checked October 24, 2026. Tick states in Trip mode above to see each one's links here.