How agarwood is graded

Ask three agarwood sellers to grade the same piece and you may get three different answers, not necessarily because anyone is lying, but because "grade" means different things in different systems, countries and parts of the supply chain. A peer-reviewed review of agarwood grading put it plainly: there is no standard quality grading system used across production, commerce and consumption.

This guide is the overview for the hub. It covers the main frameworks in use, how they overlap and where they conflict. Two detailed regional systems have their own guides: Vietnamese agarwood grading and Middle Eastern oud grading.

Why there is no single standard

Agarwood has been traded and classified independently across many producing and consuming regions for centuries, each developing its own vocabulary long before anyone tried to reconcile them. The material itself adds to the problem: no two resinous pieces are chemically identical, which leaves room for judgement even within one named system. Researchers studying agarwood smoke have described grading as flexible and subjective, often carried out by experienced sensory panels.

In practice, grade names work less like measurements and more like a shared vocabulary that still needs context. The systems below are the ones buyers meet most often. None sits above the others.

What graders actually look at

Across systems, the same handful of criteria come up again and again: resin content, whether and how well the wood sinks, colour, scent when heated, how the resin formed (natural or induced), how long it took to form, and place of origin. Different systems weight these differently, and some, like origin, are claims rather than things a grader can see.

Sinking and density

The oldest and most widespread test is whether the wood sinks. Anything denser than water, about one gram per cubic centimetre, sinks, and resin is what makes agarwood dense. The Chinese name for agarwood, chénxiāng, means "sinking fragrance," and sinking material has long been treated as the top tier. The test, and its limits, are covered in how to test agarwood at home.

Some standards turn this into density bands. A Chinese industry standard from the Fujian Eaglewood Association (T/FJEA 001-2017) sets Grade A at a density above 1.0, Grade B between 0.55 and 1.0, and Grade C between 0.43 and 0.55, alongside colour criteria. A 2026 study of Chinese agarwood found floating samples between roughly 0.45 and 0.71, partly sinking samples between roughly 0.55 and 0.91, and fully sinking samples above 1.0. Traders also speak of "full sinking," "semi-sinking" and "floating" grades, but exact cut-offs vary.

Trade terms and letter grades

Alongside density, traders use descriptive terms. "Super," "double super" and similar labels are common in Southeast Asian trade, particularly for Malaysian and Indonesian gaharu, to indicate heavy resin coverage. Letter scales such as C, B, A, AA and AAA, sometimes with numbers attached, are widely used by individual sellers to rank their own stock.

None of these terms is tied to a fixed resin percentage or density. A seller's "AAA" is a ranking within that seller's inventory, not a claim that maps onto another seller's "AAA." Size is often graded separately, especially for chips and beads, and should not be read as a proxy for resin: a small piece can be very resinous and a large one barely so.

Regional systems

Several countries have their own vocabularies. In Vietnam, kỳ nam is treated as a category apart from ordinary trầm hương, with its own colour-based sub-grades, covered in Vietnamese agarwood grading. Indonesia's national standard divides gaharu into gubal, kemedangan and powder, judged mainly on colour, weight and scent, as covered in Indonesian agarwood. In Japan, the kōdō tradition classifies incense woods into its own categories, with kyara at the top.

China has both industry and medicinal standards. Forestry and local standards use ethanol extract content and specific chromone compounds as reference indices, and the Chinese Pharmacopoeia sets minimum requirements for agarwood used as medicine. In the Gulf, origin names such as Hindi and Cambodi carry their own expectations about scent and quality, covered in Middle Eastern oud grading.

Wood, beads and oil are graded differently

Agarwood reaches buyers as chips and blocks, carved beads, powder and distilled oil, and the criteria shift with the form. Wood and chips are judged mainly by resin coverage, density, sinking and scent when heated. Beads are judged similarly, often with a stated sinking claim. Oil is graded on a different basis entirely, colour, viscosity, how the scent develops and the seller's account of origin and distillation, since the sinking test no longer applies. A "Grade A" chip and a "Grade A" oil are not measured against the same criteria.

Lab-based grading

Instrumental methods offer a more objective layer. Ethanol extract content measures how much resinous material can be extracted from a dried sample, and is used in Chinese standards. Chemical profiling by GC-MS identifies the compounds present: one study of incense smoke from four agarwood types found 2-(2-phenylethyl)chromone derivatives accounted for roughly 25 to 27 percent of the smoke profile of kynam and were not detected in the other three, and its authors suggested such markers could help grading. These methods are mostly used by researchers, larger dealers and regulators rather than at the point of sale.

What a grade tells you, and what it does not

A grade tells you how a particular seller, standard or market ranks a piece. It does not tell you the species, origin, whether the wood is wild or cultivated, or whether it has been treated, and grade names are among the easiest things to inflate. Ask any seller what their grade means to them in terms of resin, density and scent, and check the piece yourself. See fake oud: what to look for and questions to ask before you buy oud.