tomaTow

v12.3 Saved

Free towing safety calculator for cars and trucks pulling trailers.

Because “it’ll probably be fine” isn’t a spec.

Shared setup loaded. Save it?
Saved setups

Your vehicle

Auto-estimated from GVWR + max tow. Type here to enter the real value from your owner's manual.
This estimate may be optimistic. GCWR is often less than GVWR + max tow — your engine and transmission may not handle both at full capacity simultaneously.
GCWR (Gross Combined Weight Rating) is set by the manufacturer and accounts for engine power, transmission, cooling, and braking — not just adding the sticker numbers together. Check your owner's manual or the manufacturer's tow guide for the official figure. Using the real number could show you have less headroom than this estimate suggests.
Tongue limit
10% of max tow
Payload avail.
after tongue + load
GCWR headroom
GCWR − combined wt

Your trailer

Cargo capacity
GVWR − curb wt.
Current weight
curb + cargo
GVWR used
of trailer GVWR

Load configuration

Trailer cargo 0 lb
Tongue weightTongue Weight — the downward force the trailer exerts on your hitch. Typically 10–15% of your loaded trailer weight (curb + cargo).

How to measure: The most reliable method is a certified truck-stop scale (CAT scale, ~$12). Weigh the tow vehicle alone, then again with the trailer coupled — the difference is your tongue weight. Tongue weight scales (~$50–100) also work for lighter trailers.

Load placement matters: Place 60% of cargo weight in front of the trailer axle, 40% behind. Learn more →
0 lb
% of trailer 10.0%
Vehicle cargo 0 lb
PassengersPassenger Weight — estimated at 190 lb (86 kg) per person, the FAA standard average adult weight. Switch to manual entry if you prefer an exact total. 0 lb
0
Tongue weight
Eff. vehicle wt.
Combined (GCWR)

Trailer load / trailer GVWR
Trailer weight / vehicle tow rating
Tongue weight / tongue limit
Payload used / payload limit
Combined weight / GCWR
To check all limits, enter: GVWR, payload, max tow, trailer curb weight, trailer GVWR

Select a state or province to see towing rules.

Reference values only — towing laws change. Always verify with your state DMV or provincial authority before towing. Federal CDL required at 26,001+ lb (11,794+ kg) GCWR.

Auto insurance risk: Exceeding manufacturer ratings can void your coverage in an accident. An overloaded vehicle can give your insurer grounds to deny the claim.
Trailer brake laws: Most jurisdictions require trailer brakes above a weight threshold. Check the rules section above for your state or province.
CDL threshold: In the US, a commercial driver's license (CDL) may be required at 26,001 lb (11,794 kg) GCWR. This calculator flags when you approach or exceed that number.
Aftermarket mods: Lifts, airbag suspension, and sway bars affect real-world capability but don't change your manufacturer ratings — those are sticker specs for stock vehicles.
Weigh your load: This tool gives estimates. Certified scales (CAT scales at truck stops, ~$12) give actual axle weights — the only reliable way to know your tongue weight and total trailer weight.