Methodology
This page describes how the FreightTools calculators and checker work.
Formula
volume_ft3 = length_in × width_in × height_in / 1728
density_pcf = total_weight_lb / total_volume_ft3
For a shipment with several lines, the calculator adds the volume of every piece and the weight of every piece, then divides once. It never averages densities.
Conversion factors
- 1 in = 2.54 cm (exact)
- 1 lb = 0.45359237 kg (exact)
- 1 ft³ = 1,728 in³ = 0.028316846592 m³ (exact)
Rounding
No value is rounded during the calculation. Results are rounded to two decimals on screen and to four decimals in the CSV file.
What the calculator does not do
- It does not assign or certify an NMFC freight class.
- It does not apply any carrier's measurement, rounding or minimum-density rules.
- It does not assume how pieces are stacked or loaded.
- It does not check whether the dimensions or weights you enter are correct.
Quote and invoice comparison
- Amounts are handled as whole cents. Nothing is rounded except the percentage difference, which is shown to two decimals.
- Each invoice line is compared only with the quote line you matched it to. Unmatched lines count as "not in quote" or "not on invoice".
- A blank amount is unknown, not zero, and makes the result incomplete.
- If you enter the total printed on a document, that total is used and compared with the sum of its lines.
- The percentage difference is the total difference divided by the quote total. If the quote total is zero, it is not calculable.
- A quote and an invoice in different currencies are not compared.
Your data
The calculation runs in your browser. The values you enter are not sent to FreightTools.
Formula version
density-v1— initial version.comparison-v1— initial version of the comparison rules.