Urgent Shipment Calculator — Air Freight or Road?

Chargeable weight decides this, not the scale

Freight is not applied to the weight you put on the scale but to the chargeable weight. That is the greater of gross weight and volumetric weight — and the carriers write the same sentence in their own texts: DHL Express “always the greater of the actual or volumetric weight”, UPS Türkiye “the greater of the two is the billable weight”, Sürat Kargo “charged from the higher rate band”.

Chargeable weight = the GREATER of gross weight and volumetric weight · Volumetric weight = volume × the ratio for that mode

This is why the air freight premium on a light but bulky shipment comes out far larger than expected. A consignment weighing 180 kg but taking up 1.4 m³ is charged in air freight on 234 kg (1.4 m³ × 166.67 kg/m³ = 233.3, rounded up). The same consignment is 467 desi in domestic parcel traffic in Türkiye.

⚠ Compressing the packaging often earns more than negotiating the rate, because it lowers the volumetric weight directly. Sending the same item in packaging that carries less air can make a bigger difference than any percentage squeezed out of the unit price.

Two processing details affect the result directly and should be stated openly. First: the chargeable weight is rounded by the carrier’s own rule — Yurtiçi Kargo, for example, rounds below 0.50 down and 0.50 and above up, while DHL Express rounds up to the next half kilo up to 30 kg. The calculator on this page errs on the high side and rounds both modes up to the whole kilogram, and it uses that rounded figure in the cost, so the total can be reproduced from the numbers on screen. Second: in domestic parcel traffic in Türkiye, desi and kilogram are handled from the same rate band table, so the tool follows the carriers’ practice and treats 1 desi as equivalent to 1 kilogram for pricing; enter the amount per desi in the unit rate field.

Volumetric ratios by mode

⚠ These ratios change by carrier, by service type and by country, and the carriers say so themselves. IATA describes 6,000 as “defaulted” in its own system, FedEx says the divisor “varies from carrier to carrier”, and DHL Global Forwarding puts the warning “density ratios vary by location and carrier” on its own page. A concrete example: TNT’s divisor is 5,000 on its express service and 4,000 on its economy service. Ask for the divisor in writing when you confirm the freight.

Two things are deliberately absent from that table. The first is the widely repeated claim that “IATA changed the divisor from 5,000 to 6,000” on some date: there is no trace of it in IATA’s own sources, so it is not written here. The second is the divisor used by some Turkish parcel carriers whose pages could not be reached; no carrier is named on unverified figures. Confirm your own carrier’s divisor from your own contract.

On the road the rule has three terms, not two

In air and sea the comparison has two terms: kilogram and volume. In road groupage there is a third — the loading metre (ldm), the length of the trailer the consignment occupies. A long but light load looks cheap measured in kilograms and cheap measured in cubic metres; it is expensive because it blocks the length of the trailer.

The ratios these two carriers write into their own general conditions differ by 33% — and the same carrier applies a different ratio domestically and internationally: the Schenker document quoted here is its national German tariff, and for international traffic it gives no fixed figure at all but refers to the freight tables. That is why a sentence like “on the road 1 m³ is 333 kg” cannot be written: the number is not a standard, it is a contract term. Ask which one applies to your shipment, and over what scope.

⚠ The limit of the calculator on this page: it makes a two-term comparison — kilogram and volume. If the loading metre or a minimum weight per pallet comes into play in road groupage, the real freight will come out above the calculated figure. On long, narrow or non-stackable loads, treat the result as an estimate and get a written rate from the carrier.

How to find the daily cost of a delay

The hardest input is not the freight rate but the cost of a day. In most companies that number exists, but it is filed under other names.

• Downtime cost. A line or a machine standing because the part did not arrive: hourly downtime cost × shift hours.
• The late-delivery penalty in the contract. Usually written as a daily rate such as one per mille, multiplied by the contract value.
• The sale or the shipment you lose. If the goods not arriving also delays another delivery, the whole chain counts.
• The premium on an emergency purchase. If instead of waiting you would have to buy locally at a higher price, that difference can be used directly as a ceiling in place of the daily cost.
• It can also be zero. On an item where safety stock covers the gap, the daily cost of a delay really is zero — and in that case the tool recommends whichever option is cheaper.

That is why the tool’s most useful output is not the total but the break-even daily cost: the difference in total cost divided by the days gained. If a day of delay costs you more than that figure, the fast option pays. Even without knowing the daily cost precisely, saying which side of the threshold you are on is usually easy.

What is not in the freight rate

Comparing two quotes on the price per kilogram assumes both cover the same scope. On international shipments they rarely do, and on the fast option the fixed items are proportionally larger and can decide the total.

• Terminal and handling charges, separately at origin and at destination
• Customs clearance, delivery order and documentation fees
• Fuel and security surcharges — added per kilogram
• Local collection and delivery, where the rate is not door to door
• Insurance — the value of the goods is the same, but a shorter transit can be rated differently
• Duty and import VAT — not part of the freight, and depending on the delivery term they may be for the buyer’s account

The “fixed charges” fields in the calculator exist for exactly these. Left empty, the fast option looks cheaper than it is.

What the tool says when it cannot answer

The calculator is built to be able to say no, and to refuse rather than to quietly produce a figure it cannot stand behind. Four cases are reported in words.

• Road selected with no ratio entered. If either option is road groupage and the kg per m³ field is zero, the volumetric weight would collapse to zero, the chargeable weight would fall back to the gross kilograms and the cost would come out far too low. The tool refuses to calculate and asks for the ratio from your carrier’s general conditions.
• The “fast” option is not faster. If the days gained are zero or negative there is no time advantage: the tool says so, prints no break-even, and tells you either to use the cheaper option or, if the fast option is also dearer, not to use it at all.
• The fast option is already cheaper. If the difference in total cost is zero or negative there is no premium to justify, so the tool says the fast option is already cheaper and prints no break-even rather than a meaningless one.
• Which weight governed. Each chargeable weight is labelled with whether gross weight or volumetric weight decided it, so a surprising total can be traced to its cause.

How we handle this

On an urgent line we first look at whether there is a stocked equivalent inside Türkiye — because the cheapest air freight is the one you do not use. If the item genuinely has to be imported, we suggest splitting the shipment: the part that stops the work goes by air and the rest by the normal route. That usually cuts the premium to a third.

Lead time and delivery term are always stated in our quotes; where importing is involved we say so inside the quote and we do not leave open who bears duty and taxes.

Frequently Asked Questions