Ad Valorem

according to the worth of

The term "ad-valorem" is Latin for "according to value."An ad-valorem tax (Latin: by value) is a tax based on the value of real estate or personal property. An ad-valorem tax is typically imposed at the time of a transaction (a sales tax or value-added tax (VAT)), but it may be imposed on an annual basis (real or personal property tax) or in connection with another significant event (inheritance tax or tariffs). A related concept is the fixed-rate tax, in which the tax base is the quantity of something, regardless of its price. For example, in the United Kingdom, a tax on the sale of alcoholic drinks is calculated on the quantity of alcohol in the drink, rather than its price.
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Adverb
1. in proportion to the estimated value of the goods taxed; "the goods were taxed ad valorem"
(synonym) ad val

valorem, part of the term "ad valorem" meaning "according to value"

A term used to denote a duty or charge laid upon goods, at a certain rate per cent upon their value, as stated in their invoice, -- in opposition to a specific sum upon a given quantity or number; as, an ad valorem duty of twenty per cent.