Transparent calculations

Methodology & sources

The formulas, planning references and limitations behind ShipMeasure. Source-dependent assumptions are dated so you can see what needs checking before a commercial decision.

Reviewed 25 Aug 2026Primary sources where availablePlanning estimates clearly labelled
Core principle: ShipMeasure separates mathematics that is stable (for example cubic volume) from commercial or equipment assumptions that can change (for example carrier rounding, dimensional divisors, pallet limits and container specifications).

CBM and volume

For a rectangular package measured in centimetres, ShipMeasure calculates cubic metres as L × W × H × quantity ÷ 1,000,000. For mixed cargo, each line is calculated separately and the volumes are summed. The tools expect the external packed dimensions because those describe the physical space occupied by the shipment.

Cubic feet are converted from cubic metres using 1 m³ ≈ 35.3147 ft³. CBM is a physical volume result; it is not by itself a freight price or a guarantee of how much cargo will fit into a container.

Dimensional and chargeable weight

The general metric calculation used by the dimensional-weight tools is DIM kg = L(cm) × W(cm) × H(cm) ÷ divisor. For a planning chargeable weight, ShipMeasure compares actual and dimensional weight for each cargo line and sums the higher result for each line. This avoids the error that can occur when dense and bulky packages are aggregated before the comparison.

ProfileShipMeasure planning factorPublic source reviewedWhat to verify
DHL Express UK5,000 cm³/kgDHL weight & dimensions ↗Service limits, measurement/weight rounding and your applicable rate terms.
FedEx UK5,000 cm³/kg example/defaultFedEx dimensional weight ↗FedEx notes the divisor can vary by carrier/customer context; check the service and contract.
UPS UK5,000 cm³/kgUPS size & weight guide ↗UPS publishes its own measurement and weight-rounding instructions; apply the current service guide.
Air freight planning6,000 cm³/kgPlanning profile, not a carrier promiseUse the divisor in the airline/forwarder quote or tariff.

ShipMeasure does not reproduce every carrier's size thresholds, large-package rules, surcharges, minimum billable weights or negotiated rates. The carrier profiles are therefore labelled as indicative planning calculations rather than quotes.

Packaging break-even

If a package is DIM-limited, the volume at which dimensional weight equals actual weight is target cm³ = actual kg × divisor. The percentage reduction shown is 1 − target volume ÷ current volume, floored at zero. If length and width are held constant, a theoretical target height can be calculated as target volume ÷ (length × width). This is geometry only; it does not prove that a smaller package is safe or practical.

Pallet planning

The pallet planner tests six orthogonal rotations of a rectangular carton. For each orientation it calculates whole cartons along the pallet length and width (TI), then checks how many layers fit beneath the user-entered maximum loaded height and gross-weight limit. The plan with the highest whole-carton capacity is selected, using footprint utilisation as a tie-breaker.

ProfilePlanning footprint/baseStatus
EUR / EPAL1200 × 800 × 144 mm; approx. 25 kg tare referenceEPAL product data ↗
UK standard1200 × 1000 mm planning profileCommon footprint; actual pallet construction/tare varies.
US GMA48 × 40 in (1219.2 × 1016 mm) planning profileCommon footprint; verify supplier/pool specification.
Australian1165 × 1165 mm planning profileCommon footprint; verify supplier/pool specification.

ShipMeasure does not certify stack strength, pallet working load, load stability, crush resistance, overhang, interlocking, product orientation or handling safety. The user-entered maximum gross weight and loaded height are planning constraints, not automatically safe limits.

Dry-container references

The current dry-container profiles use Hapag-Lloyd published equipment examples. Hapag-Lloyd explicitly notes that specifications vary by manufacturer, so ShipMeasure treats these values as references rather than guaranteed equipment dimensions.

ContainerInternal dimensions usedNominal capacityExample max payloadSource
20' Standard5.900 × 2.352 × 2.395 m33.2 m³28,130 kgHapag-Lloyd ↗
40' Standard12.032 × 2.352 × 2.395 m67.7 m³28,750 kgHapag-Lloyd ↗
40' High Cube12.032 × 2.350 × 2.700 m76.3 m³28,600 kgHapag-Lloyd ↗

The standalone carton-fit tool tests the six orthogonal box orientations and applies the example payload when carton weight is entered. The main workspace separately compares total shipment CBM and weight with the reference capacity. Neither method is a full 3D mixed-SKU bin-packing or certified stowage plan.

LCL W/M and LCL-vs-FCL comparison

ShipMeasure models a common ocean-LCL weight-or-measurement basis as W/M = max(total CBM, gross kg ÷ 1,000, minimum entered). DHL Global Forwarding explains that LCL shipment cost is based on whichever of volume and weight is larger and notes that origin/destination charges form additional parts of a typical LCL invoice.

DHL Global Forwarding: cost drivers of LCL rates ↗

The LCL estimate is W/M × user-entered rate + user-entered fixed charges. FCL values are entirely user supplied. The displayed break-even is a simplified comparison against those inputs; it does not model every surcharge or prove a universal LCL/FCL crossover.

Freight-cost allocation

For volume, weight, quantity or value allocation, each SKU receives its proportion of the selected total basis. For the hybrid method, ShipMeasure calculates each SKU's normalized volume share and normalized weight share, then uses 50% × volume share + 50% × weight share. Allocated freight per piece is the SKU allocation divided by its quantity.

This is a management-costing tool, not accounting or tax advice. Duties, recoverable taxes, brokerage, insurance and other landed-cost elements may need separate allocation rules.

Review policy and corrections

Stable mathematical formulas do not need frequent revision, but external carrier/equipment references do. The source-dependent assumptions on this page were reviewed on 25 August 2026. ShipMeasure will update a source-dependent profile when a primary source shows a material change. If you spot an outdated assumption, email contact@shipmeasure.com.

For operational shipments, always compare ShipMeasure's planning output with the carrier, forwarder, warehouse or equipment provider responsible for the actual movement.