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cans

The American can industry describes the dimensions of cylindrical cans by two three-digit numbers. The first number is the can's diameter and the second its height. In each number, the first digit is the number of whole inches, and the second two digits are the number of sixteenths of an inch. So, for example, a 303 by 407 can would be 3 ⁰³⁄₁₆ inches in diameter and 4 ⁰⁷⁄₁₆ inches high.

The table below lists some common can sizes.

Traditional name	Capacity in fluid oz.	Dimensions in inches	Can industry
202	4	2⅛ by 2⅞	202 by 214
Tall 202, 6Z	5	2⅛ by 3½	202 by 308
8-Z short	7	2 ¹¹⁄₁₆ by 3	211 by 300
8Z tall			211 by 304
No. 1 (Picnic)	10	2 ¹¹⁄₁₆ by 4	211 by 400
Tall no. 1	12	2 ¹¹⁄₁₆ by 4 ¹³⁄₁₆	211 by 413
300	14	3 by 4 ⁷⁄₁₆	300 by 407
303	16	3 ³⁄₁₆ by 4⅜	303 by 406
Short no. 2	14	3 ⁷⁄₁₆ by 3⅜	307 by 306
No. 2	19	3 ⁷⁄₁₆ by 4 ⁹⁄₁₆	307 by 409
Tall no. 2	24	3 ⁷⁄₁₆ by 5 ⁹⁄₁₆	307 by 509
No. 2½	28	4 ¹⁄₁₆ by 4 ¹¹⁄₁₆	401 by 411
No. 3	32	4¼ by 4⅞	404 by 414
Tall no. 3	46	4¼ by 7	404 by 700
2 lb coffee	66	5⅛ by 6½	502 by 608
No. 10 (same as 3-lb coffee can)	105	6³⁄₁₆ by 7	603 by 700

Cans of milk were formerly sealed by drops of lead, a process abandoned in the 1980s because of lead’s toxicity. Sweetened condensed milk cans now hold 14 ounces av. (formerly 15); cans of evaporated milk hold 5 or 12 fluid ounces (formerly 6 or 14½).

Can Manufacturers Institute.
CMI Voluntary Can and End Dimension Reference Manual.

History

Standard can sizes had appeared at least as early as the 1870s.

There are certain sizes of can that are regarded as standard but unfortunately are not based upon any unit of volume nor upon average domestic requirements. Most of them have originated in trying to make a certain number of cans out of a sheet of tin plate of a certain size, the logical alternative of making the sheet of tin plate to such a size as will build cans of certain capacity does not seem to have been considered. The regular No. 2 can is too large for peas, corn, and beans in amount for the average family to use at one time, and the unused part is not as attractive when reheated. The No. 3 can of tomatoes is likewise an anomaly though the objection is not so strong as for the No. 2. The No. 2½ can was introduced as a compromise on the No. 3, especially for fruits, but recently a better size is being used having the diameter of the No. 2½ but only half the height. After machines have once been built to make and close cans of a certain size, it is difficult to make changes no matter how desirable it may be.

A. W. Bitting and K. G. Bitting.
Canning and How to Use Canned Foods.
Washington, D.C.: National Canners Association, 1916.

The standard size of tin plate in the United States was 14 inches by 20 inches.

Although volume was not a factor in sizing (except for the #10, a gallon), weight apparently was:

The above machinery is adapted to making both 2-lb. and 3-lb cans, which are the ones mostly used. One box of tin plate will make 270 3-lb. cans or 370 2-lb cans.…

Standard Sizes for Cans.

No. 1 Cans,	1-lb	Diameter 2¾ in.	Height 4 in.
No. 2 "	2-lb	" 3 7/16 in.	" 4 9/16 in.
No. 3 "	3-lb	" 4 3/16 in.	" 4 7/8 in.
No. 6 "	6-lb	Double the capacity of the No. 3
No. 10 "	1-Gal	Diameter 6¼ in.,	Height 7 in.

Ernest F. Schwaab.
The Secrets of Canning. A Complete Exposition of the Theory and Art of the Canning Industry.
Baltimore: John Murphy and Co., 1890.

resources

Another superb video by Bill Hammack, this one The Ingenious Design of the Aluminum Beverage Can.