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Air vs sea break-even calculator
Enter the sea rate per CBM and volume, the air rate per chargeable kilogram and weight, and the transit days for each mode. The calculator returns both freight totals, the premium and the value per day saved that the faster option needs to create.
The premium per day covers the freight difference only; duty, insurance, inventory carrying cost, stock-out losses, fees and the actual routing schedule must be added before choosing a mode.
What the premium per day means
Air freight is faster and more expensive. The premium is the difference between the air charge and the sea charge for the same shipment. Dividing it by the days saved gives the value per day that the faster route must create to be worth its cost.
That value can come from earlier sales, lower safety stock, avoiding a stock-out, or releasing cash sooner. It is not a recommendation: a high premium per day is acceptable only if the product earns more than that in the same period. The air share output shows how much of the combined freight bill is air, which is useful when explaining the choice to a buyer.
Chargeable weight versus volume
Air cargo is usually billed on chargeable weight, the greater of actual weight and volumetric weight. Volumetric weight comes from volume divided by a carrier divisor, so light, bulky cargo pays for space rather than mass. The field asks for chargeable kilograms directly; calculate it from the forwarder's divisor before entering it.
Sea freight is quoted per cubic metre, per container or per revenue tonne, depending on the service. This model uses a per-CBM rate and a CBM volume. Do not mix units: a sea rate quoted per container needs a different comparison, and a rate quoted per kilogram is not the same product as a per-CBM rate.
Costs outside the freight quote
The comparison covers freight only. Duty, import tax, insurance, port and terminal charges, customs clearance, documentation and door delivery can differ by mode and route, and some apply to one option but not the other. Inventory carrying cost, cash tied up in transit, spoilage and stock-out loss also belong in the decision.
Schedules matter as much as averages. A 28-day saving is not real if the sea service is reliable and the air service misses its cut-off. Use current quotes for the actual lane and season, then add the non-freight lines before choosing. The calculator does not decide the mode and does not replace a forwarder's quote.
Frequently asked questions
Is air freight always priced per chargeable kilogram?
Most air rates use chargeable weight, but the divisor, rounding and minimum charge are set by the carrier or forwarder. Confirm how the quote treats volumetric weight and whether fuel and security surcharges are included.
What does the premium per day tell me?
It is the extra freight cost divided by the days saved. The faster mode is justified only if the shipment creates at least that much value per day through earlier sales, lower stock or avoided stock-outs.
Should inventory carrying cost be added?
Yes, when you make the final decision. It is not in this calculation. Add the cost of capital tied up during the longer sea transit, plus storage and obsolescence risk, to the sea option.
Why is the air share so high?
Air freight often costs several times more than sea for the same shipment, so it dominates the combined bill. The percentage describes the split, not whether air is the better choice.
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