Not sure if this has been posted before, but this site: web.customs.gov.tw/rate/rate/esearch.asp , may help when calculating import taxes. This is especially useful when using couriers such as DHL, FedEx, USP. For some reason they are extremely precise, as opposed to items sent via USPS (airmail).
To use the search engine you enter the name of your product. You may need to play around with it. For example, it does not recognize’ nutritional’, but ‘vitamins’ is accepted. A;so, it does not accept ‘scuba’, but ‘water-sports’ (with the hyphen) is accepted.
Note that in addition to the rate shown in column one (probably the one we would use the most), there also appears to be an additional 5% VAT or BT (whatever the heck that is).