How it works
Cross-check multiple entered weight ratings instead of treating the advertised maximum tow rating as the only limit.
This is the Ireland planning view, with monetary inputs and outputs in EUR. A currency label does not establish that a tax rate, construction price, coverage rule or legal limit has been verified locally. The inputs and limitations below describe the actual scope.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
8-
?unitSystem=Measurement systemChoice · Optional · Default: metric · Accepted values: imperial, metric
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?gcwr=Manufacturer gross combination weight ratingNumber · Required · Default: 6,000
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?loadedVehicle=Actual loaded tow-vehicle weight before trailer tongueNumber · Required · Default: 2,500
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?towRating=Configuration-specific manufacturer trailer ratingNumber · Required · Default: 3,000
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?payloadRemaining=Actual remaining vehicle payloadNumber · Required · Default: 500
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?tonguePercent=Measured/expected trailer tongue-weight fractionPercentage · Required · Default: 12
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?hitchTrailerLimit=Hitch trailer-weight ratingNumber · Required · Default: 3,000
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?hitchTongueLimit=Hitch tongue-weight ratingNumber · Required · Default: 350
Outputs
4-
combinationLimitTrailer allowance from combination ratingNumber
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payloadLimitTrailer allowance from remaining payloadNumber
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hitchLimitTrailer allowance from hitch tongue ratingNumber
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limitingWeightLowest entered arithmetic trailer allowanceNumber · Primary output
Formula
arithmetic trailer allowance = minimum(combination rating − loaded vehicle, vehicle tow rating, remaining payload/tongue fraction, hitch rating, hitch tongue rating/tongue fraction).
Calculations retain numeric precision internally. Displayed values are rounded for readability. Quantities that must be purchased as whole units are rounded up only where the formula explicitly requires it.
Read the inputs before calculating
- Manufacturer gross combination weight rating: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Actual loaded tow-vehicle weight before trailer tongue: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Configuration-specific manufacturer trailer rating: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Actual remaining vehicle payload: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Measured/expected trailer tongue-weight fraction: Enter the quantity described by the label.
- Hitch trailer-weight rating: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Hitch tongue-weight rating: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
Reproducible worked example
The following is a fictional arithmetic example, not a local quote, a verified claimant or a market forecast. Its values are included so the formula can be checked. The form does not automatically confirm any verification checkbox.
| Input | Example value |
|---|---|
| Manufacturer gross combination weight rating (kg) | 6,000 |
| Actual loaded tow-vehicle weight before trailer tongue (kg) | 2,500 |
| Configuration-specific manufacturer trailer rating (kg) | 3,000 |
| Actual remaining vehicle payload (kg) | 500 |
| Measured/expected trailer tongue-weight fraction | 12 |
| Hitch trailer-weight rating (kg) | 3,000 |
| Hitch tongue-weight rating (kg) | 350 |
| Output | Calculated result |
|---|---|
| Trailer allowance from combination rating | 3,500 kg |
| Trailer allowance from remaining payload | 4,166.6667 kg |
| Trailer allowance from hitch tongue rating | 2,916.6667 kg |
| Lowest entered arithmetic trailer allowance | 2,916.6667 kg |
Interpreting a changed assumption
Start with one complete scenario and change only one input when diagnosing a difference. Recheck units, the period of every rate, whether an amount is recurring or one-off, and whether a cost is already included elsewhere. A larger calculated benefit is not evidence that an assumption is more likely to occur.
Limitations
- Prices, consumption and contract terms are entered scenarios. This is not a retail quote, tax eligibility determination or vehicle safety certification.
- Not a safe-to-tow certification. Axle/tire ratings, actual scale weights, braking, load distribution, passengers/cargo, coupling type, speed, license and local law can impose additional limits. An exceeded combination rating is not cured by this zero-clamped output.
Frequently asked questions
What does this Towing Rating Cross-Check result represent?
Cross-check multiple entered weight ratings instead of treating the advertised maximum tow rating as the only limit. It applies the displayed formula to your inputs; it does not infer omitted facts.
Are the starting amounts verified Ireland prices or legal rules?
No. Numeric defaults are illustrative unless an input or dated reference explicitly identifies a researched component. Currency is EUR; local quotes, eligibility and unsupported rules must be entered and verified separately.
What must I check before relying on the result?
Prices, consumption and contract terms are entered scenarios. This is not a retail quote, tax eligibility determination or vehicle safety certification.
Can I compare or share different assumptions?
Change one assumption at a time and use the browser-local project or share controls. A shared URL contains the encoded input values; do not include information you do not wish to disclose.
Sources and reference scope
- DOE energy-use arithmetic — retrieved 2026-09-24. Energy consumption versus power; not a local tariff or an approval of this implementation.
- NIST unit conversion guidance — retrieved 2026-09-24. Unit definitions; geometry and financial arithmetic in these worksheets are explicitly stated.
- CFPB loan-estimate explanation — retrieved 2026-09-24. US cost components; the general amortization formula is stated separately.
These references support only their stated scope. They are not evidence that every local rule or price needed by the master expansion has been loaded.