Allocating freight and duty across the lines of an order

Split a freight bill across order lines in proportion to what drives the freight: weight (or volume) when the carrier charges by weight, value when weight is unknown or the charge follows value, quantity only when the units are alike. The method can move a cheap item's landed cost by 20 % or more, so choose it deliberately, state it next to the result, and make the shares add up to the bill.

Quotes and landed cost · 29 September 2026 · Proceny

The order

One shipment from one supplier, four lines, and a freight bill of 240.00.

Four order lines
Line	Qty	Unit price	Value	Weight each	Weight
Cable, 100 m drum	10	180.00	1,800.00	25 kg	250 kg
Junction box	200	6.00	1,200.00	0.4 kg	80 kg
Terminal block	2,000	0.50	1,000.00	0.02 kg	40 kg
LED panel	20	50.00	1,000.00	3.5 kg	70 kg
Total	2,230		5,000.00		440 kg

The same 240.00, four ways

Each method gives a line its share: the line's value (or quantity, or weight) divided by the order's total, times the bill. "Per line" gives every line the same amount.

Freight allocated to each line
Line	By value	By quantity	By weight	Per line
Cable drum	86.40	1.08	136.36	60.00
Junction box	57.60	21.52	43.64	60.00
Terminal block	48.00	215.25	21.82	60.00
LED panel	48.00	2.15	38.18	60.00
Total	240.00	240.00	240.00	240.00

What that does to each unit, as a share of its price:

Freight per unit, as a percentage of the unit price
Line	By value	By quantity	By weight	Per line
Cable drum (180.00)	4.8 %	0.1 %	7.6 %	3.3 %
Junction box (6.00)	4.8 %	1.8 %	3.6 %	5.0 %
Terminal block (0.50)	4.8 %	21.5 %	2.2 %	6.0 %
LED panel (50.00)	4.8 %	0.2 %	3.8 %	6.0 %

By quantity, the terminal blocks — 40 kg of a 440 kg shipment — carry 90 % of the freight and look 21.5 % more expensive than they are, while the heavy cable drums travel almost free. By value, every line pays the same 4.8 %, which is simple and never absurd, but ignores that the drums are what filled the truck.

Which method when

Method	Fair when	Misleads when
Weight (or volume)	The carrier charges by weight or space — pallets, parcels, sea and air freight	Weights are missing or guessed; for air, the chargeable weight is often volumetric
Value	Weights are unknown, or the charge follows value (insurance, some courier fees)	Light, expensive items share a load with heavy, cheap ones
Quantity	Units are alike in size and weight	Pieces and drums are mixed, as above
Per line	The charge is per line — picking, labelling, a documentation fee	Used for freight on lines of very different size

Whatever you choose, use the same method when you compare suppliers, and write it next to the landed cost. Two landed costs calculated two different ways cannot be compared.

In Excel, adding up to the bill

With the basis (value, quantity or weight) in D2:D5 and the bill in a cell named Freight:

Share (rows 2–4)   =ROUND(Freight * D2 / SUM($D$2:$D$5), 2)
Share (last row)   =Freight - SUM(E2:E4)
Landed unit cost   =(Value + Share) / Qty

Rounding every share on its own can leave the total a cent off the invoice; giving the remainder to the last (or largest) line keeps it exact. If a supplier quotes per 100 or per pack, turn that into a price per unit first — see price per 100 and pack size changes. To compare several suppliers with freight split by value, use the free quote comparison template.

Where duty fits

Duty is not split like freight: it is a rate per line, set by each item's tariff classification, applied to that line's customs value. What the customs value includes depends on where you import. In the EU it normally includes transport and insurance up to the EU border; the US generally excludes international freight and insurance. Your customs broker confirms the rules for your shipments. The order of work is therefore:

Allocate freight and insurance to the lines (above).
Build each line's customs value: goods, plus its freight and insurance share where your rules include them.
Apply each line's own duty rate to that value.
Add handling and other charges, then divide by quantity for the landed cost per unit.

With a hypothetical 2.7 % duty on the cable, freight allocated by weight: an EU-style customs value of 1,800.00 + 136.36 = 1,936.36 gives 52.28 of duty; a value without freight, 1,800.00, gives 48.60. Recoverable VAT or sales tax usually stays out of landed cost, since you reclaim it.