Last updated: 2026-05-27 | Author: Master Chen Bao, Head Distiller, SilkwayOud
Quick answer: Oud grading is based on one physical rule: resin content as measured by density relative to water. Floating grade is below 0.85 g/cm3. Sinking grade is above 1.05 g/cm3. Between them sit Standard A, Super, and Double Super. Higher density means more resin, deeper scent, longer burn, higher price.
The marketing layer of oud grading is confusing on purpose. Sellers use "Super King," "Royal A++++," "Imperial Cambodi" and dozens of other names that look impressive and mean nothing without context. The physical layer is simple. There is only one number that matters: density.
The single rule
Resin is denser than wood. The more resin packed inside a chip, the heavier it is for its size. Drop it in water. If it sinks, the resin content is above 50%. If it floats, the resin content is below 30%. Everything between is a sliding scale.
The 6 grades buyers actually see
| Grade | Density g/cm3 | Resin % | Color | Best use | Typical price/g (Maoming) |
|---|---|---|---|---|---|
| Floating | <0.85 | 5-15% | Light tan | Daily incense, beginner | $3-12 |
| Standard A | 0.85-0.95 | 15-30% | Amber | Daily wear oil, attar base | $15-60 |
| Super | 0.95-1.00 | 25-40% | Dark amber | Mid-tier oil, daily chips | $60-120 |
| Double super | 1.00-1.05 | 40-55% | Brown-black | Premium oil, ceremony | $120-300 |
| Sinking grade | 1.05-1.15 | 55-70% | Deep black, oil-sheen | Collector pieces, royal use | $300-800 |
| Kyara (rare) | >1.15 | 70%+ | Resin-black, dense | Auction-only | $1,500-8,000 |
Kyara grade is essentially unobtainable on retail markets and requires specific botanical conditions found mostly in Vietnam and parts of Japan.
How Maoming graders sort
Our plantation sorts in three steps:
- Visual color and oil sheen (rough triage)
- Hand weight against calibrated reference chips
- Water test for the top three grades
A senior grader sorts about 80 kg of mixed-grade chips per day. The result determines pricing within a 20x range, so accuracy matters more than speed.
Why "A-grade" without origin means nothing
A floating-grade Cambodian chip can be marketed as "A-grade Cambodi." A floating-grade Maoming chip can be marketed as "A-grade Chinese." The "A" tells you nothing without (a) the country of origin, (b) the density measurement, and (c) the species. A buyer's first question should always be: "What is the density in g/cm3 and which species?"
For verified Maoming grades, see our Grade A Heating Chips and our top-tier Sinking-Grade Oud Nuggets.
What you should pay
Use the table above as a sanity floor. If a seller offers sinking-grade at $80/g, the math does not work. Either it is not sinking-grade, or it is not real, or both. Read our deep dive on why oud is so expensive for the supply chain economics.
Frequently asked questions
Is sinking-grade always the best choice?
No. For daily heating chips, Grade A or Super is more practical. Sinking-grade is for collectors, formal use, and meditation pieces. The scent is fuller, but the price-per-session is hard to justify daily.
How do I verify a "sinking-grade" claim?
Drop a chip into water. If it sinks within 10 seconds, the claim holds. If it sits suspended or floats, push back on the seller.
What is Kyara?
The top historical grade, traditionally Vietnamese or Japanese. Density above 1.15 g/cm3, resin content above 70%. Almost no Maoming reaches Kyara. Auction pieces only.
Why does grade affect oil more than chips?
Higher-grade chips distill 3-5x more oil per kilo than lower-grade. A sinking-grade kilo yields 18-22ml of oil. A floating-grade kilo yields 3-5ml. That ratio is the bulk of the price gap in oils.
Related reading: Chinese Oud vs Indian Oud | How to Spot Real Agarwood | Why Is Oud So Expensive?