Core formulas
| Calculation | Planning formula |
|---|---|
| Trailer payload | GVWR − actual empty trailer weight |
| Estimated tongue load | Loaded trailer weight × tongue/pin percentage |
| Truck payload used | Passengers + cargo + hitch hardware + tongue/pin load |
| Combined actual weight | Loaded tow vehicle before trailer + total loaded trailer weight |
| Dump trailer volume | Length × width × side height ÷ 27 (from cubic feet to cubic yards) |
| Material weight | Cubic yards × planning density |
| Estimated trailer axle load | Loaded trailer weight − estimated tongue/pin load |
Why we ask users for ratings
Vehicle configuration matters. Tow rating, payload and combined-weight limits can differ across cab, bed, engine, drivetrain, axle ratio and option packages. The safest general-purpose approach is to let users enter the ratings from their exact labels and official manufacturer documentation rather than silently choosing a generic database value.
Material-density estimates
Bulk material is inherently variable. The gravel, soil, sand, mulch and debris presets are planning numbers only. Moisture, compaction, particle size and source can change actual weight. We therefore keep a custom-density option and repeatedly recommend scale verification when operating near capacity.
Corrections
If you find a formula, copy or usability issue, please contact us. Changes should improve both accuracy and transparency.