AGS Cut Grade Chart — Full 0–10 Scale and AGS↔GIA Cut-Grade Comparison (2026)
A single-page reference for the AGS cut grade chart: every number from 0 (Ideal) through 10 (Poor), what each tier means under the AGS Performance Grading Standard, and the line-by-line GIA cut-grade equivalent the trade uses to translate AGS Platinum (pre-2022) and AGS Ideal supplement (2023+) scores into GIA Excellent / Very Good / Good / Fair / Poor. Lower is better — the opposite direction from the GIA scale.
The AGS cut grade chart, 0 to 10
The AGS Performance Grading Standard ray-traces the stone, measures brightness, contrast, dispersion, and leakage, and combines them with proportion, polish, and symmetry into a single continuous number from 0 to 10. 0 is the top performance tier (Ideal — the bucket the trade calls AGS 0); 10 is the bottom of the scale. The chart below is the cut-grade line only — the headline number most buyers mean when they say "AGS cut grade." Polish, symmetry, color, and clarity run on the same 0–10 numeric scale and are mapped in a second table below.
| AGS | Label | What it means | GIA cut-grade equivalent |
|---|---|---|---|
| 0 | Ideal | Brightness, contrast, dispersion and leakage all in the top performance bucket under ASET ray-tracing. Often paired with 0 polish + 0 symmetry on the same report and written AGS 000 (triple-zero). The top 10–15% of GIA Triple Excellents. | GIA Excellent + AGS Ideal 0 supplement on the same stone |
| 1 | Excellent | One tier below Ideal — typically a measurable leakage band or minor contrast asymmetry that the ASET image surfaces. Visually almost identical to AGS 0 to a non-trade eye; trades 3–7% lower per carat on naturals above ~$5,000. | GIA Excellent (without AGS 0) |
| 2 | Very Good | Roughly the middle of the GIA Excellent proportion band with one or two light-performance metrics measurably softer than tier 1. | GIA Excellent (low end) to GIA Very Good |
| 3 | Good | Proportions or polish/symmetry visibly off-target; leakage or weak contrast becomes legible in the ASET image even to a non-trade eye. | GIA Very Good to low GIA Good |
| 4 | Fair | Material leakage or proportion mismatch; the stone is functional but visibly underperforming relative to a well-cut comparable. | GIA Good to GIA Fair |
| 5 | Poor | First clearly poor tier — light return is compromised even without instruments. | GIA Fair |
| 6 | Poor | Pronounced leakage or proportion error. | GIA Poor |
| 7 | Poor | Same — deeper into the poor band. | GIA Poor |
| 8 | Poor | Same. | GIA Poor |
| 9 | Poor | Same. | GIA Poor |
| 10 | Poor (bottom of scale) | Worst-case grade the AGS 0–10 scale prints. | GIA Poor |
The AGS 0 vs AGS 1 step is where the per-carat dollars live. On a 1.00 ct round natural at a $7,500/ct retail comp, an AGS 0 verdict typically carries a 3–7% cut premium over AGS 1 on the same color and clarity — even though a non-trade observer cannot reliably tell the two stones apart at arm's length. The premium pays for verified light performance, not visible difference, and that is the whole point of the AGS scale. To anchor the per-carat band the AGS 0 premium attaches on top of, see the live 2026 diamond price-per-carat index.
AGS 0, AGS 000, AGS Ideal — what the labels mean
- AGS 0 — the cut grade line alone reads 0 on the 0–10 scale. Top-tier light performance under the AGS Performance Grading Standard.
- AGS 000 (triple-zero) — 0 cut + 0 polish + 0 symmetry, all three at the top of scale on the same report. The trade pays a premium over a stone that scored 0 cut but slipped to 1 on polish or symmetry; always verify which three lines are at zero before paying the AGS 000 premium.
- AGS Ideal — the verbal label for the AGS 0 tier; also the brand name of the 2023+ digital supplement (AGS Ideal Report) that GIA now attaches to qualifying GIA Diamond Grading Reports for ~$25 per stone after acquiring the AGS methodology in 2022.
- AGS Platinum Light Performance Diamond Quality Document — the standalone pre-2022 AGS Laboratories report format. No new ones have been issued since late 2022; the historical database remains queryable at agslab.com.
AGS 0–10 across polish, symmetry, color and clarity
An AGS Platinum report uses the same 0–10 numeric scale for every grading axis — not just cut. The mapping to the standard GIA letter / category conventions:
| Axis | AGS range | GIA equivalent |
|---|---|---|
| Polish | 0–10 | 0 = GIA Excellent, 1 = Excellent (slightly softer), 2 = Very Good, 3 = Good, 4 = Fair, 5–10 = Poor |
| Symmetry | 0–10 | 0 = GIA Excellent, 1 = Excellent (slightly softer), 2 = Very Good, 3 = Good, 4 = Fair, 5–10 = Poor |
| Color | 0.0–10.0 in 0.5 steps | 0.0 = D, 0.5 = E, 1.0 = F, 1.5–2.0 = G, 2.5 = H, 3.0–3.5 = I, 4.0 = J, 4.5–5.5 = K–M, 6.0–7.5 = N–R, 8.0–10.0 = S–Z |
| Clarity | 0–10 in 1-point steps | 0 = FL, 1 = IF, 2 = VVS1, 3 = VVS2, 4 = VS1, 5 = VS2, 6 = SI1, 7 = SI2, 8 = I1, 9 = I2, 10 = I3 |
How GIA absorbed the AGS methodology
GIA did not fold AGS scoring into its own cut grade. GIA's own cut grade — Excellent through Poor on proportion measurements plus polish, symmetry, and a face-up appearance check — was unchanged by the 2022 acquisition. What GIA did was bolt the AGS Performance Grading Standard onto the side of the existing GIA report as a separately-priced supplement. The mechanics, in order:
- The software moved. The ray-tracing engine, the AGS-proprietary scoring layer on top, and the ASET imaging pipeline all transferred to GIA's Carlsbad infrastructure.
- The research staff moved. Senior AGS cut researchers transferred to GIA roles, carrying the institutional knowledge of how the standard was tuned and which edge cases had historically been the hard calls.
- A new product wrapper launched. GIA released the AGS Ideal Report as a digital, QR-linked supplement to a GIA Diamond Grading Report (or GIA Laboratory-Grown Diamond Report) for roughly $25 per stone on top of the base GIA report fee. The supplement prints AGS 0 on stones that pass.
- The standalone AGS Platinum report stopped. No new AGS Platinum Light Performance Diamond Quality Documents have been issued since late 2022.
- The historical database stayed open. agslab.com still resolves report-number lookups against pre-2022 paper, so a 2014 AGS 0 stone you own today is verifiable on the original lab's archived database.
The practical consequence for 2026 buyers: a stone that earns AGS 0 on a freshly-issued GIA + AGS Ideal supplement is, methodologically, the same verdict the same stone would have earned from AGS Laboratories in 2021. Same software, same standard, often the same researchers reviewing edge cases. The full closure timeline, the line-by-line walk through a pre-2022 AGS Platinum report, and the legacy-report value cases sit in the deep-history companion at AGS cut grade — full history and how to read a legacy AGS report.
AGS cut grade vs GIA cut grade — the head-on comparison
The two scales score the same physics from different angles. GIA cut grade is a five-bucket categorical verdict (Excellent / Very Good / Good / Fair / Poor) built from proportion measurements, polish, symmetry, and a face-up appearance check. AGS cut grade is an eleven-step continuous numeric verdict (0–10) built from ray-traced light performance — brightness, contrast, dispersion, leakage — plus proportion, polish, and symmetry. AGS's 0 sits at the top of GIA's Excellent band; the AGS Ideal supplement on a 2026 GIA report is the way to print both verdicts on one stone. For the full head-on rubric — what each lab actually prints on the document, and when to insist on which paper — see AGS vs GIA: side-by-side grading rubric and the deep methodology hub at AGS vs GIA: cut grade and when each matters. For the three-lab decision that adds IGI, see GIA vs IGI vs AGS.
Frequently asked questions
How do you read the AGS cut grade chart?
Top to bottom, lowest is best — the opposite direction from the GIA cut scale. 0 is Ideal (the top performance bucket, called AGS 0 in the trade; AGS 000 means 0 cut + 0 polish + 0 symmetry on the same report). 1 is Excellent, 2 is Very Good, 3 is Good, 4 is Fair, and 5 through 10 walk down through Poor performance with 10 the bottom of the scale. The chart is a continuous numeric verdict on how the stone actually performs with light under the AGS Performance Grading Standard ray-tracing model.
What is the GIA equivalent of AGS 0?
AGS 0 maps to the top of GIA Excellent plus the AGS Ideal 0 supplement on the same stone — the methodology GIA absorbed from AGS in 2022 and now ships as a $25 digital supplement to a GIA Diamond Grading Report or GIA Laboratory-Grown Diamond Report. AGS 1 maps to GIA Excellent without the AGS Ideal supplement. AGS 2 maps to the low end of GIA Excellent or GIA Very Good. AGS 3–4 cover GIA Very Good through GIA Fair. AGS 5–10 are GIA Fair through Poor.
Does the AGS 0–10 scale still apply to 2026 reports?
Yes. AGS Laboratories stopped issuing standalone AGS Platinum Light Performance Diamond Quality Documents in late 2022, but the AGS Performance Grading Standard — the ray-tracing methodology behind the 0–10 chart — transferred to GIA and now prints on the AGS Ideal Report, a digital QR-linked supplement to a current GIA report. Same software, same standard, same scientists, new wrapper. A 2026 GIA + AGS Ideal supplement that prints AGS 0 is methodologically identical to a pre-2022 AGS Platinum 0.
What is the difference between AGS 0 and AGS 000?
AGS 0 is the cut-grade line alone. AGS 000 (triple-zero) means 0 cut + 0 polish + 0 symmetry — all three top-of-scale on the same report. The trade pays a premium for the triple zero over a stone that scored 0 cut but slipped to 1 on either polish or symmetry; verify which three lines are at zero before paying the AGS 000 premium.
Where do the AGS color and clarity 0–10 numbers sit against GIA letters?
On the same AGS 0–10 scale. Color: 0.0 = D, 0.5 = E, 1.0 = F, 1.5–2.0 = G, 2.5 = H, 3.0–3.5 = I, 4.0 = J, 4.5–5.5 = K–M, 6.0–7.5 = N–R, 8.0–10.0 = S–Z. Clarity: 0 = FL, 1 = IF, 2 = VVS1, 3 = VVS2, 4 = VS1, 5 = VS2, 6 = SI1, 7 = SI2, 8 = I1, 9 = I2, 10 = I3. The numeric scale is the AGS convention; the GIA letter / category convention is the dominant 2026 paper trail.
How do you verify an AGS cut grade on a pre-2022 AGS Platinum report?
Look up the report number at agslab.com — the historical database is preserved and now archived under GIA — and confirm the returned grades match the document in front of you. Then match the laser-inscribed report number on the girdle to the paper using a 10x loupe before money moves. If the lab database has no record of the number, the document is fabricated; if the girdle inscription does not match the paper, the paper is not for the stone.
Read alongside
- AGS cut grade — full history and how to read a legacy AGS report — the long-form companion: 1996 launch, 2005 light-performance pivot, 2022 closure, GIA absorption, line-by-line read of a pre-2022 AGS Platinum document, and dollar-anchored legacy-report value cases.
- Diamond cut grade explained — the broader cut-quality framework the AGS scale fits inside.
- GIA cut grade comparison — the same physics scored on the GIA Excellent–Poor scale, for translating between the two systems on a specific stone.
- How to read a GIA diamond report — the line-by-line walkthrough of the modern GIA report that the AGS Ideal supplement now attaches to.
- 2026 diamond price-per-carat index — the round and fancy-shape per-carat bands by carat weight and GIA / IGI grade that an AGS 0 cut premium attaches on top of.