Towing and trailer weight calculators
Nine free tools for working out what you can actually tow. Every one shows the formula it uses, walks through a worked example, and links the standard or regulation it comes from. Nothing runs on a server - the arithmetic happens in your browser.
Start here
Most people arrive wanting a tow rating and leave realising payload was the real limit. If you only run one calculation, run payload - it is the number that stops most half-ton trucks long before the tow rating does. If you are chasing a sway problem, start with tongue weight.
All calculators
- Tongue Weight Calculator Find your target tongue weight and check a measured value against the safe range.
- Towing Capacity Calculator Work out what you can actually tow once passengers, cargo and tongue weight are counted.
- Trailer Axle Weight Calculator Split trailer weight across axles and check each one against its rating.
- Trailer Axle Weight Chart Common axle capacities, what a bare axle weighs, and how to identify the axle you have.
- Weight Distribution Hitch Calculator See how much load a WD hitch moves back to the front axle, and whether you need one.
- Payload Capacity Calculator What is left of your truck payload after people, gear and the trailer tongue.
- GVWR Margin Calculator How close a loaded trailer is to its GVWR, and how much cargo is left.
- Trailer Payload Calculator How much cargo a trailer can legally carry, from GVWR and empty weight.
- Hitch Class Selector Which receiver class covers your trailer weight and tongue weight.
Guides
- How to Calculate Tongue Weight (and Why 10-15% Matters) The formula, three ways to measure it for real, and what happens at the edges of the range.
- Towing Capacity vs Payload vs GVWR: What Actually Limits You Four ratings, and why the one that stops you is almost never the tow rating on the brochure.
- How to Weigh a Trailer at a CAT Scale The two-weighing method that gives you every number these calculators ask for.
Why another towing calculator
Most towing calculators give you a number and no reasoning. That is a problem in a subject where the answer depends on which of four simultaneous ratings binds first, and where being wrong means a trailer swaying at highway speed.
So every tool here shows its formula, works an example by hand, states which regulation or standard the numbers come from, and says plainly when the honest answer is "weigh it". Where a figure is a rule of thumb rather than a specification, it says that too.
Verify before you tow. These are planning aids, not professional or engineering advice. Your real limits are on your vehicle's door placard, your trailer's VIN plate and your owner's manual, and those override anything calculated here.