The cost of air freight is primarily determined by the weight and volume of the shipment, the type of goods being transported, the distance between the origin and destination, and the level of service required (e.g., express or standard). Charges can also be influenced by fuel prices, security surcharges, and airport fees. For lighter shipments, the cost may be calculated based on the volume (dimensional weight) rather than the actual weight, as space is a premium resource on aircraft.