Ask three agarwood sellers to grade the same piece of wood and you may get three different answers, not necessarily because one of them is lying, but because "grade" means different things depending on which system, which country, and which point in the supply chain you're asking about. There is no single global standard for agarwood grading, no equivalent of a diamond's universally recognised carat-clarity-cut-colour framework.
This guide is the overview for this hub: it covers the major grading frameworks actually in use across the trade, how they overlap and where they conflict, and what each one can and can't tell a buyer. Two of the most detailed regional systems, Vietnam's and the Gulf market's, get their own dedicated guides linked throughout this page.
Why There's No Single Grading Standard
Agarwood grading varies by country, by trader, and even within a single country's domestic market, and there is no single commonly accepted standard, even within individual countries. Part of this comes down to how the trade developed: agarwood has been bought, sold, and classified independently across dozens of producing and consuming regions for centuries, each developing its own vocabulary before any international standard-setting body existed to reconcile them. Part of it comes down to the wood itself, since no two resin-infused pieces are chemically identical, which leaves real room for subjective judgment even within a single named system.
The practical result is that grading terms function less like fixed measurements and more like a shared vocabulary that still requires context. "Grade A" from one seller is not guaranteed to mean the same thing as "Grade A" from another. The systems below are the most commonly encountered frameworks, not a single hierarchy that supersedes the others.
The Sinking Test: Density and Water
The oldest and most widely used grading method across the trade is the sinking test, sometimes called the water test. Agarwood with a density greater than 1 gram per cubic centimetre will sink in water, a property driven directly by resin content: the more resin saturating the wood, the denser and heavier it becomes relative to its size. In Chinese trade terminology this top tier is referred to as chen xiang, literally "sinking fragrance."
Within sinking material, the trade further subdivides by how completely a piece sinks, often described in terms of a sinking rate or "points." Material that sinks at a rate of around 90 percent or higher is generally treated as top-tier, first-grade material; sinking rates between roughly 70 and 90 percent are treated as second-grade; and rates between roughly 50 and 70 percent fall into a third-grade category. Below that, material is often described as semi-sinking or floating, with correspondingly lower resin content and lower market value. These percentage bands are widely used trade reference points rather than a formally codified international standard, and exact cutoffs vary somewhat between sellers and regions.
Want to know what resin content actually measures, and how it's estimated?
Resin Content: What It Means and How to Measure ItResin Saturation Terms: Super, Double Super, Triple Super
A second, overlapping vocabulary describes resin saturation directly using descriptive terms rather than a sinking percentage. "Super" generally indicates a high degree of resin coverage visible across the wood's surface; "Double Super" indicates an even higher degree of coverage and is a term commonly used in the Malaysian and Indonesian markets in particular. In the Malay and Indonesian trade, the largest, most heavily saturated pieces are sometimes pushed a level further and called "Triple Super."
These terms are descriptive rather than standardised against a fixed resin percentage, which is part of why the same physical grade can carry different labels in different markets. Cambodia, for example, refers to what would be an "AB" grade elsewhere in the trade as "Triple King Super," illustrating just how far regional naming can diverge even when the underlying wood quality is comparable.
Letter and Number Scales
A third common approach uses letter grades, typically ascending through some combination of C, B, AB, A, AA, and AAA, sometimes paired with a separate 1-to-5 numeric scale layered on top. As with the saturation terms above, there is no fixed, universally agreed mapping between a letter grade and a specific resin percentage or sinking rate; sellers generally use these scales as an internal ranking within their own stock rather than as a claim that maps precisely onto every other seller's "A" or "AAA."
Size is sometimes graded as a separate axis entirely, particularly for finished products like beads and chips, using descriptive size tiers such as "Baby," "Baby King," "King," and "Queen." Size and resin saturation are independent measurements: a small piece can carry very high resin content, and a large piece can carry comparatively little, so size-tier names should not be read as a proxy for quality grade.
Regional Naming Systems
Beyond these general frameworks, several producing and consuming regions have developed their own detailed classification systems, often layering origin, grade, and trade nickname together in a single name. Vietnam's system separates kỳ nam from ordinary trầm hương as a distinct top category, with its own internal sub-grades, covered in full in our Vietnamese agarwood grading guide. Indonesia's national standard classifies agarwood into categories including gubal gaharu, kemedangan, and serbuk gaharu, based primarily on colour, weight, and odour rather than a sinking percentage.
The Gulf market layers a different system on top of all of this: regional origin names like Hindi, Cambodi, and Trat function partly as grade indicators in their own right, since each name carries trade-recognised expectations about scent profile and quality tier, independent of any letter or sinking grade attached to the same piece. This system, and how it interacts with the origin guides covered elsewhere on this site, is covered in our Middle Eastern oud grading guide.
Wood, Beads, and Oil Are Graded Differently
Agarwood reaches buyers in several distinct forms, raw chips and blocks, carved beads and jewellery, powder, and distilled oil, and the primary grading criteria shift depending on which form is being assessed. Raw wood and chips are judged mainly by the sinking test, visual resin coverage, and weight relative to size. Beads are judged similarly, but sinking rate is often quoted as a specific percentage since beads are a more standardised, comparable unit than irregular chips. Oil is graded on an entirely different basis: colour, viscosity, fragrance development over time, and increasingly, laboratory chemical profiling rather than anything resembling a sinking test, since oil has already been separated from the wood that test depends on.
This distinction matters for buyers comparing claims across product types. A "Grade A" wood chip and a "Grade A" oil are not being measured against the same criteria, even when a seller uses identical terminology for both.
Lab Verification: GC-MS and Density Testing
For high-value purchases, instrumented testing offers a more objective alternative to trade vocabulary. Gas chromatography-mass spectrometry, or GC-MS, can identify and quantify the specific aromatic compounds present in agarwood oil or resin, giving a chemical fingerprint that goes well beyond what visual grading or a sinking test can establish. Density measurement, weighing a sample and calculating volume to get a precise density figure, offers a more rigorous version of the basic sinking test, since it produces an exact number rather than a binary sink-or-float result.
These lab methods are not generally available to home buyers at the point of sale, but they are increasingly used by serious dealers, researchers, and some certification efforts to verify grading claims independently. For everyday purchases, the home-applicable versions of these same principles, weight, density, and sensory checks, are covered in our guide to testing agarwood authenticity at home.