Potato sizing chart: sizes, carton counts and grades

A potato sizing chart has three separate scales, and a USDA quote usually names two of them. Size designations such as Size A, Size B and Creamer are set by diameter or weight. Carton counts size a 50 lb box of russets by how many potatoes fill it. Grades such as US No. 1 measure condition, with only a minimum size attached. All three come from USDA's potato standards.

USDA size designations

The size designations are defined in 7 CFR 51.1545. Diameter there means the widest measurement across the potato at right angles to its length.

• Creamer: 3/4 inch to 1 5/8 inches.
• Size B: 1 1/2 to 2 1/4 inches.
• Size A: at least 1 7/8 inches, with at least 40 percent of the lot 2 1/2 inches across or 6 ounces or larger. No maximum.
• Small: at least 1 3/4 inches, up to 2 1/2 inches or 6 ounces.
• Medium: 2 1/4 inches or 5 ounces, up to 3 1/4 inches or 10 ounces.
• Large: 3 inches or 10 ounces, up to 4 1/2 inches or 28 ounces.
• Chef: 2 3/4 inches or 8 ounces, up to 4 1/2 inches or 28 ounces.

Size A and Size B overlap between 1 7/8 and 2 1/4 inches. What sets a Size A lot apart is the 40 percent share of bigger potatoes it has to carry, which makes A the larger table size and B the smaller one. Red, yellow and white round potatoes are quoted this way on the shipping point report.

Carton counts are a weight scale

Russets for the carton trade are sized by count instead: the number of potatoes that fill a 50 lb carton. The same section of the standards gives each count a weight range per potato:

• Under 50: 15 ounces and up.
• 50-count: 12 to 19 ounces.
• 60-count: 10 to 16 ounces.
• 70-count: 9 to 15 ounces.
• 80-count: 8 to 13 ounces.
• 90-count: 7 to 12 ounces.
• 100-count: 6 to 10 ounces.
• 110-count: 5 to 9 ounces.
• 120-count and up: 4 to 8 ounces.

Worked example. A 50 lb carton holds 800 ounces, so a 70-count averages about 11.4 ounces a potato, inside its 9 to 15 ounce band, and a 40-count averages 20 ounces. The bands overlap: a 12 ounce potato fits a 60, a 70 or an 80-count carton, because the count names roughly how many potatoes fill the box while the band sets how small or large any one of them may be. The table below is the live russet ladder, each count's price per hundredweight this week; the low counts, the big bakers, usually carry the premium. Carton counts explained covers why.

Size and price run differently by variety

Bigger is not always dearer. This site keeps every same-day pair where a district quoted Size A and Size B of the same variety in the same pack, both US No. 1. Size B reds sold above Size A reds on 98 percent of more than 5,200 such pairs, a median 38 percent higher per hundredweight. Yellows, whites and long whites ran the other way: Size B never sold above Size A, and the median discount ran 30 to 39 percent. On September 17, 2026, Big Lake and central Minnesota Size B reds in 50 lb sacks quoted $18.00 against $10.00-12.00 for Size A. The red potato price page tracks the Size A benchmark across origins.

Grades sit on top of size

A grade is not a size. US No. 1 carries its own floor of 1 7/8 inches and US No. 2 a floor of 1 1/2 inches, unless another size is specified with the grade (7 CFR 51.1541 and 51.1543), which is how a quote can read US No. 1, Size B. The grade measures shape and defects: how badly a potato can be misshapen and how much of it a defect would cost to trim. For what the grade does to price, see how potato grades affect FOB price and the live US No. 2 vs US No. 1 pairs.