Timeliness & Price
Actually, after takeoff, the delivery duration of express shipping to your door is within 3-5 working days, faster than that of air freight within 7-9 working days. And, their prices are almost the same shown a soaring and unstable trend.
Package Size & Weight
The weight of a single parcel without surcharge is 12-21 kg. There will be the overweight fee for over 21 kg per parcel, and the oversize fee for the longest side over 121 cm or the second longest size over 75cm per parcel.
Customs Duties & Difference
Air freight fee covers US customs taxes, but express shipping fee won’t cover that when product value exceeds $800. Volumetric weight per carton of air & sea freight = LWH/6000, and LWH/5000 for express shipping.