Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Payload remaining (lb)
100
Tongue weight (lb)
900
Total payload capacity (lb)
1,600
Maximum trailer weight (lb)
10,000
Margin vs your trailer (lb)
2,500
Payload used
93.8%
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter vehicle gvwr (lb).
- 2Enter curb weight (lb).
- 3Enter gcwr (lb).
- 4Enter passengers + gear (lb).
- 5Enter loaded trailer weight (lb).
- 6Enter tongue weight (% of trailer).
- 7Read your payload remaining (lb) on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Payload, not tow rating, is what most people exceed first — tongue weight lands on the truck's rear axle and eats into the same payload as passengers and cargo.
Worked example
Using the values the calculator loads with:
Inputs
- Vehicle GVWR (lb): 7000
- Curb weight (lb): 5400
- GCWR (lb): 16000
- Passengers + gear (lb): 600
- Loaded trailer weight (lb): 7500
- Tongue weight: 12 % of trailer
Results
- Payload remaining (lb): 100
- Tongue weight (lb): 900
- Total payload capacity (lb): 1,600
- Maximum trailer weight (lb): 10,000
- Margin vs your trailer (lb): 2,500
- Payload used: 93.8%
What each field means
Inputs
- Vehicle GVWR (lb)
- The vehicle gvwr (lb) used in the calculation. Starts at 7000 so you have a working example on load.
- Curb weight (lb)
- The curb weight (lb) used in the calculation. Starts at 5400 so you have a working example on load.
- GCWR (lb)
- The gcwr (lb) used in the calculation. Starts at 16000 so you have a working example on load.
- Passengers + gear (lb)
- The passengers + gear (lb) used in the calculation. Starts at 600 so you have a working example on load.
- Loaded trailer weight (lb)
- The loaded trailer weight (lb) used in the calculation. Starts at 7500 so you have a working example on load.
- Tongue weight (% of trailer)
- The tongue weight used in the calculation, measured in % of trailer. Starts at 12 % of trailer so you have a working example on load. Accepted range: 5–25 % of trailer.
Results
- Payload remaining (lb)
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Tongue weight (lb)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total payload capacity (lb)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Maximum trailer weight (lb)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Margin vs your trailer (lb)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Payload used
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the towing capacity & payload calculator work?
Payload, not tow rating, is what most people exceed first — tongue weight lands on the truck's rear axle and eats into the same payload as passengers and cargo. The underlying maths is: Available payload = GVWR − curb weight − passengers − cargo − tongue weight.
What do I need to enter?
6 values: vehicle gvwr (lb), curb weight (lb), gcwr (lb), passengers + gear (lb), loaded trailer weight (lb), and tongue weight. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the payload remaining (lb) result mean?
It is returned as a whole number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary.
Who is this tool for?
It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Towing Capacity Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/towing-capacity
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/towing-capacity" target="_blank" rel="noopener">Towing Capacity Calculator — RevenueLab</a> (2026).</p>
Source: [Towing Capacity Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/towing-capacity) (2026).