The short answer: A5 is the top grade the Japan Meat Grading Association gives a Wagyu carcass. The letter (A to C) rates how much meat the carcass yields, and the number (1 to 5) rates quality, set by the lowest of four scores. A5 needs marbling of BMS 8 or higher, and BMS 5 to 7 caps a carcass at 4.
What does A5 Wagyu mean?
A5 is the highest grade a Japanese Wagyu carcass can get: A for yield, the best of three, and 5 for meat quality, the best of five [1]. A certified grader from the Japan Meat Grading Association (JMGA) assigns it to the whole carcass after slaughter, under one national standard.
The two halves are scored separately and printed together, so there are 15 possible grades, from A5 down to C1. A carcass can be an A3 or a B5.
The grade describes the carcass. It doesn't record the farm, the feed, the cow's age or how she lived. We cover what that leaves out in What makes Peak Wagyu special?.
What does the letter (A, B or C) measure?
The letter measures yield: how much usable meat the carcass gives relative to its size [1]. It says nothing about taste. JMGA calculates a "yield standard value" from four measurements: the ribeye area, the thickness of the rib meat, the chilled carcass weight, and the thickness of the fat under the skin. Big ribeyes and thick rib meat raise the number, while a heavy carcass and thick outer fat lower it.
| Yield grade | Yield standard value | Meaning |
|---|---|---|
| A | 72 or higher | Better than standard |
| B | 69 to under 72 | Standard |
| C | Under 69 | Below standard |
Takemitsu-chan's ribeye measured 51 cm² and her rib meat 7.7 cm thick, on a 468.2 kg carcass. Her yield standard value came to 73.5, which is an A.
How is the quality number (1–5) scored?
The quality number is the lowest of four separate scores, so one weak area pulls the whole grade down [1]. A carcass that scores 5 on color, firmness and fat but 4 on marbling is graded 4.
| Quality grade | Marbling (BMS) | Meat color (BCS) | Firmness and texture | Fat color (BFS) |
|---|---|---|---|---|
| 5 | No. 8–12 | No. 3–5, very good luster | Very firm, very fine texture | No. 1–4, very good luster and quality |
| 4 | No. 5–7 | No. 2–6, fairly good luster | Fairly firm, fairly fine | No. 1–5, fairly good |
| 3 | No. 3–4 | No. 1–6, standard | Standard | No. 1–6, standard |
| 2 | No. 2 | No. 1–7, near standard | Near standard | No. 1–7, near standard |
| 1 | No. 1 | Anything outside No. 1–7 | Poor firmness or coarse texture | Anything outside No. 1–7 |
BCS, the Beef Color Standard, rates the red of the lean on a numbered scale, along with its luster. BFS, the Beef Fat Standard, rates the color of the fat, along with its luster and quality. Firmness and texture have no number scale; the grader judges how firm the meat is and how fine its grain looks.
What is BMS, and how does it map to the grade?
BMS is the Beef Marbling Standard, a 12-step scale for how much fat runs through the lean. It's the number to read past the letter, because it carries more detail than the grade does. The quality grade only has five steps for marbling, and BMS has twelve [1].
| BMS | Marbling grade | Note |
|---|---|---|
| 1 | 1 | |
| 2 | 2 | |
| 3–4 | 3 | |
| 5–7 | 4 | USDA Prime is about BMS 5 [2]; Takemitsu-chan is BMS 6 |
| 8–12 | 5 | The only range that can grade A5 |
Two things follow from that table. First, BMS 6 is always an A4 or lower. A5 needs BMS 8 at minimum, so a BMS 6 carcass can't reach it, however well it scores on color, firmness and fat. Second, an A4 at BMS 6 already sits above the ceiling of USDA Prime, the top US grade.
So when a label says "A5" alone, you know the marbling is somewhere between BMS 8 and 12. Ask for the BMS, because BMS 8 and BMS 12 sit four steps apart on the scale.
A4 vs. A5: what's the difference?
The difference is quality, and for most carcasses that means marbling. Both can carry the same A for yield. A5 is BMS 8 to 12, the richest beef the scale measures. An A4 is usually BMS 5 to 7: still heavily marbled, with more beef character and less richness per bite.
A5 is also less rare than the pitch suggests. Of the 538,612 Wagyu carcasses JMGA graded in 2025, 62.5% were A5 and 21.6% were A4 [3]. Ten years earlier, in 2015, the A5 share was 26.9% [4]. Among female Wagyu like Takemitsu-chan, 52.6% graded A5 in 2025 [3].
| A4 | A5 | |
|---|---|---|
| Yield | A (72+) | A (72+) |
| Marbling | Usually BMS 5–7 | BMS 8–12 |
| Lowest quality score | 4 | 5 |
| Eats like | Rich, with clear beef flavor | Very rich; a few bites go a long way |
| Share of 2025 Wagyu carcasses [3] | 21.6% | 62.5% |
| Our current cow | Takemitsu-chan, A4, BMS 6 |
Ellie Takeda, who raised Takemitsu-chan, sends her cows off before they reach maximum weight, and calls the result "an approachable, easy-to-eat quality." In her words: "Wagyu isn't only Grade 5 — there's wagyu you can enjoy every day, too."
A4 also changes how much you serve. Plan on about 4–8 oz per person, against an 8–12 oz Angus steak; our A4 eats well at the top of that range or beyond. Cooking has the method, and the FAQ has more on why we picked her.
What does a real grading record look like?
A real grade belongs to one carcass, and you can tie it to that animal's 10-digit ID. Here is Takemitsu-chan's, as JMGA graded her at its Himeji office:
| Field | Takemitsu-chan |
|---|---|
| Grade | A4 |
| BMS | 6 |
| Breed | Kuroge Washu (Japanese Black) |
| Sex | Female |
| Carcass weight | 468.2 kg |
| Ribeye area | 51 cm² |
| Rib thickness | 7.7 cm |
| Yield standard value | 73.5 |
| Carcass number | 3469 |
| Individual ID | 1493019197 |
JMGA issues a grading certificate keyed to the individual ID, in Japanese, English or Chinese [5]. It goes to the producer, the shipper, or a business that bought the carcass or its cuts. Consumers can't request one, so ask your seller. Anyone can look up the ID itself in Japan's national cattle registry [6], which confirms the breed, birth date and slaughter date behind the grade.
Her full record is on her page, and every box ships with a Certificate of Authenticity carrying her ID. To check any Wagyu you buy, see how to tell if Wagyu is real. For how regional brands use the same grades, see Kobe beef vs. Wagyu.
Frequently asked questions
What does A5 Wagyu mean?
A5 is the highest grade the Japan Meat Grading Association (JMGA) gives a carcass. "A" means the carcass yields more usable meat than standard, and "5" means it scored top marks for marbling, meat color, firmness and texture, and fat color. The overall quality number is the lowest of those four scores.
What is the difference between A4 and A5 Wagyu?
Yield can be the same "A" for both. The difference is quality, usually marbling. A5 needs a marbling score of BMS 8 to 12, and BMS 5 to 7 caps a carcass at A4. A4 beef is still heavily marbled; it eats with more beef character and less richness per bite.
What is BMS in Wagyu?
BMS is the Beef Marbling Standard, a 12-step scale for marbling, the fat that runs through the lean. JMGA maps it to the marbling grade, with BMS 8–12 for a 5, 5–7 for a 4, 3–4 for a 3, 2 for a 2 and 1 for a 1.
Is A4 Wagyu good?
Yes. A4 is the second-highest quality grade, and its marbling range of BMS 5 to 7 starts around where USDA Prime tops out. Takemitsu-chan, the cow in our current drop, graded A4 with BMS 6.
How common is A5 Wagyu?
Common, in Japan. Of the 538,612 Wagyu carcasses JMGA graded in 2025, 62.5% were A5 and 21.6% were A4. In 2015 the A5 share was 26.9%.
Sources
- Japan Meat Grading Association, beef carcass trading standards (牛枝肉取引規格)
- Snake River Farms, "Deep Dive into SRF Beef Grades" (maps BMS 5 to USDA Prime)
- Japan Meat Grading Association, beef carcass grading results by breed and sex, January–December 2025 (spreadsheet)
- Japan Meat Grading Association, beef carcass grading results by breed and sex, January–December 2015 (spreadsheet)
- Japan Meat Grading Association, services, including the beef carcass grading certificate (牛枝肉格付結果証明書)
- National Livestock Breeding Center, cattle individual identification search (English)
