A5 Wagyu has become so famous that it can sound like the name of a beef category. In reality, A5 combines two separate parts of Japan's grading system: a letter describing estimated carcass yield and a number describing meat quality.

The Japan Meat Grading Association separates yield from quality, which is essential for understanding grades such as A4, B5 or C5 and for avoiding the idea that the letter A simply means “best tasting.”

What do A, B and C mean?

The letters are yield grades. A indicates yield above the standard, B indicates standard yield and C indicates yield below the standard. They do not directly score flavour, tenderness or marbling.

What do quality grades 1 to 5 mean?

The number represents meat quality, with 5 the highest. Four groups are assessed: marbling; meat colour and brightness; firmness and texture; and fat colour, brightness and quality.

The final quality grade is constrained by the lowest-scoring criterion, so spectacular marbling alone cannot produce quality grade 5 if another criterion falls short.

How does BMS fit in?

The Beef Marbling Standard runs from 1 to 12. BMS 8–12 satisfy the marbling criterion for quality grade 5; 5–7 for grade 4; 3–4 for grade 3; 2 for grade 2; and 1 for grade 1.

See our BMS guide for more detail.

Why can two A5 products be different?

One A5 carcass may have BMS 8 while another has BMS 12. Both are yield A and quality 5, but marbling intensity differs. Cut anatomy also changes what you see in individual steaks.

What does A4 mean?

A4 combines yield A and quality 4. The marbling criterion for grade 4 corresponds to BMS 5–7. Some diners prefer this balance because it can feel less rich than extreme A5.

What does B5 mean?

B5 is yield B and quality 5. It demonstrates why letter and number must be read separately: the quality number remains the maximum even though yield is not A.

Is A5+ an official higher grade?

No. The official system ends at A5. Some retailers use A5+ commercially to refer to very high BMS or other characteristics, so buyers should ask what the plus sign actually means.

The grade belongs to the carcass

A5 is assigned to the carcass, not independently to each retail steak. Ribeye and tenderloin from the same animal still have different anatomy, fat distribution and eating characteristics.

Meat colour matters

Colour and brightness are assessed against standards. The goal is not simply darker or lighter red; it is whether the meat falls within the appropriate quality range.

Firmness and texture matter too

Muscle structure is another part of the assessment. High marbling cannot simply override a lower result in firmness and texture.

Fat is also evaluated

Fat colour, brightness and quality form their own criterion. This shows that Japanese grading is multidimensional rather than a single marbling contest.

Regional brand and grade are different

A5 does not mean Kobe, Miyazaki or Matsusaka. Grade describes the carcass; a regional brand applies additional origin and production rules.

How to read a product page

Check origin first, then the letter-and-number grade, then BMS if provided. After that, look at cut, weight, format and traceability. A marbling photograph alone cannot supply all of this information.

The conclusion

Japanese grading combines yield and quality, and A5 is only one of fifteen possible combinations. A means above-standard yield; 5 is the highest quality grade based on marbling, meat colour, firmness and texture, and fat characteristics.

Once letter, number and BMS are separated, the system becomes a practical buying tool rather than a mysterious premium label.

Frequently asked questions

Is A5 the highest grade?

It combines the highest yield category A with the highest quality grade 5.

Is B5 worse quality than A5?

Both are quality grade 5; their yield grades differ.

Does BMS 12 guarantee A5?

No. Other quality criteria must also qualify and yield must be A.

Is there an A6?

No. The official quality scale ends at 5.

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