Interactive tool
Boat tow capacity calculator
Add up every pound going on the trailer — boat, trailer, fuel, and gear — and check it against your tow vehicle's rated capacity. We follow the 80% rule: keep total towed weight at or below 80% of capacity for a safe, comfortable tow.
Enter all five fields for the most accurate verdict. Leave a field blank to skip it.
Manufacturer's rated tow capacity for your vehicle & hitch combination.
Rigged dry weight from the builder, including engine(s).
Empty single-axle ~600–1000 lb; tandem ~1000–1800 lb.
Auto-converted at 6 lbs/gal. Add water tank weight in gear if applicable.
Coolers, anchors, batteries, water toys, canvas, etc.
The 80% rule is a long-standing guideline that leaves headroom for hills, wind, emergency maneuvers, and the additional weight you'll inevitably add over time.
Green — Safe
Total towed weight is at or below 80% of capacity. Standard towing is fine; keep an eye on tire pressure and tongue weight.
Amber — Marginal
Total weight is between 80–100% of capacity. Slow down, increase following distance, and re-check hitch, brakes, and tire ratings before a long haul.
Red — Overloaded
Total weight exceeds rated capacity. Do not tow. Reduce load or upgrade your tow vehicle.
- • Check your tongue weight too — aim for 10–15% of total trailer weight on the hitch.
- • Trailer brakes are usually required above 1,500–3,000 lb (varies by state). Confirm yours work.
- • Account for fuel in the tow vehicle and passengers — they reduce payload, not tow rating, but still matter.
- • Inflate trailer tires to the sidewall max, not the door-jamb pressure.
- • Re-check weight after adding batteries, wakeboard towers, or T-tops — they add up fast.
About tow capacity vs. payload
Tow capacity is what the vehicle can pull; payload is what it can carry (including tongue weight from the trailer). Two numbers, both matter. A small SUV may list a 3,500 lb tow rating but only 800 lb of payload — a 400 lb tongue weight plus four passengers and cargo will overload the axle before you ever reach the tow limit. Use this calculator as a first-pass sanity check, then confirm against your vehicle's tire-and-loading sticker (usually on the driver's door jamb) and your trailer's GVWR placard. When in doubt, scale-weigh the loaded rig at a commercial CAT scale — it costs a few dollars and tells you the truth.