Know Before You Tow.

Check your towing limits before you hitch up

TowLoadCheck is a towing capacity calculator for iPhone, built for anyone pulling a travel trailer, RV, boat or horse trailer. Enter the ratings off your door label, tow guide and trailer label, and it checks payload, GVWR, GCWR, maximum loaded trailer weight and tongue weight together, then tells you plainly whether you are within limits.

Download on the App Store

$0.99 — one-time purchase. No subscription, no ads, no in-app purchases.
For iPhone, iOS 15.1 or later. US price shown; App Store pricing varies by country.

TowLoadCheck app icon
How it works

See TowLoadCheck in Action

Enter it once, check it in seconds. No guessing, no spreadsheets.

“Check your towing limits before you go” — TowLoadCheck results screen showing Within Entered Ratings, with trailer GVWR at 87.1%, vehicle payload at 85.0% and GCWR at 80.0%, closest limit first “See exactly where you're over limit” — TowLoadCheck results screen showing Rating Exceeded, with vehicle payload the most exceeded at 102.6%, 40 lb over its rating “See how load changes affect your limits” — TowLoadCheck What If? screen adding 300 lb of vehicle load and showing each rating change, with vehicle payload rising from 85.0% to 104.6% “Start with your vehicle and trailer ratings” — TowLoadCheck Your Rig screen listing the tow vehicle’s payload, GVWR, max trailer and GCWR ratings and the trailer’s GVWR, empty weight, type and tongue estimate “Account for passengers and gear” — TowLoadCheck Today’s Load screen adding the driver, a passenger, cargo, accessories and hitch equipment, with 1,190 of 1,529 lb payload used “Include your trailer's full load” — TowLoadCheck Today’s Load screen calculating the loaded trailer from empty weight, cargo, fresh water and other load, at 6,100 of 7,000 lb trailer GVWR
Why it matters

Your tow rating is only one limit

A tow vehicle has more than one limit, and it is possible to sit comfortably under the advertised towing capacity while still exceeding your payload, your combined weight rating, or the maximum loaded trailer weight in your tow guide. Tongue weight, passengers, fuel, water and gear all count against those numbers.

Working it out by hand means digging the figures out of the door frame and the owner's manual, then keeping a spreadsheet honest. TowLoadCheck runs that arithmetic against every rating you have entered at once and names the one your real setup reaches first, so you find out in the driveway rather than on the scale or at a roadside inspection.

What you get

Built for the way you actually load

Every rating checked at once

Vehicle payload, trailer GVWR, maximum trailer rating, GCWR, tongue weight and your receiver and hitch limits are checked together, so a combination cannot pass on one number while quietly failing another.

See how much headroom is left

The results screen names the rating you are closest to, how much of it you have used and how many pounds remain, alongside an estimate of the trailer weight you still have room for.

Try it before you load it

The What If tool lets you change the numbers and see the effect immediately, so you can work out what has to come off before you start moving gear.

Shows its working

Open the calculation details to see exactly which figures produced the verdict. Nothing is a black box you have to take on trust.

Saved vehicles and trailers

Store each tow vehicle and trailer once, then switch between them. Checking a different combination takes seconds rather than a fresh round of data entry, and your saved profiles can sync through iCloud to your other devices.

Works offline, no account

Once your details are saved the calculations run without a connection and without signing up for anything. Works in US or metric units. Useful at the storage yard, the boat ramp and the campground.

Find out before you hitch up

Download on the App Store

Pay once, use it for good — no subscription, no ads.
Available for iPhone. Android is on the roadmap.

TowLoadCheck compares the weights and ratings you enter. It does not determine whether a vehicle and trailer combination is safe to operate. Always follow your vehicle, trailer, hitch, tire and equipment manufacturers' ratings and instructions.