GaugeWatcher vs TowCalc

Simple river flow data. No signup required. No ads. No fluff. Find nearby gauges, check flow rates, bookmark favorites. That's it.

See every towing limit at once, before you leave the yard. TowCalc turns your tow vehicle ratings, your hitch ratings and a trailer weight into a clear read on how safely you are loaded. Enter the numbers off the door jamb label and a scale ticket, and the app checks every limit and tells you how much headroom is left. WHAT IT DOES - GVWR: the loaded vehicle against its rating, with the payload you have used and what is left. - GCWR: the vehicle and trailer together against the combined rating, with headroom to spare. - Tongue weight: the percent on the ball against the healthy 10 to 15 percent target, and the exact weight to aim for. - Axle and hitch checks: the combined front and rear axle rating, and the hitch tongue and trailer ratings, for a weight carrying or a weight distributing setup. - Largest trailer: the single biggest trailer this rig can pull, with the weakest link named, whether that is the combined rating, the payload, or the hitch. - Clear warnings the moment any limit is passed or the tongue is too light or too heavy. - Metric or imperial throughout: pounds or kilograms. SAVE YOUR RIGS Save each truck as a profile and keep the trailers you tow as loads under it. Reopen a rig in one tap, compare loads on a chart across your history, and watch the app grow more useful the more you tow. Nothing leaves your iPhone. LOAD PLACEMENT GUIDE See how to shift the load to land in the tongue weight target, and an estimate of how the tongue adds weight to the rear axle and lifts it off the front, from your wheelbase and hitch overhang. Practical loading tips included. FREE AND PRO The full single calculation is free, forever. The one-time Pro unlock adds saved vehicle profiles and loads, the load placement guide, and export. There is no subscription: pay once and keep it. PRO EXPORT Export a per-rig PDF tow sheet with the ratings and every load, and a CSV of your whole library, straight from the share sheet. PRIVATE BY DESIGN No account, no cloud, no tracking. Every rig you enter stays on your device. TowCalc is a planning aid, not a certified weight. Always confirm actual weights on a certified scale and follow your vehicle and hitch ratings before towing.