Rubber Band Sizes: Size Chart by Number, #8 to #172
Rubber band sizes are numbered by width first, then by length. Sizes #8 to #22 are 1/16 inch wide, #27 to #38 are 1/8 inch, #57 to #69 are 1/4 inch, and the wider and longer bands follow, with flat lengths from 7/8 inch to 8 1/2 inches. Flat length is half the band's circumference. The most popular sizes are #16, #18, #19, #32, #33 and #64, and #64, 3 1/2 x 1/4 inch, is the size most often called a standard rubber band.
Find a rubber band for a bundle
Enter the bundle's width and thickness, such as a stack of envelopes or cards. The finder works out the distance around the bundle and shows how far each stocked band has to stretch to wrap it once. Alliance rates its bands to break at 700 to 775 percent stretch, so choose a band that wraps the bundle with plenty of stretch to spare; the wider the band, the tighter the hold. Bands that would stretch less than 10 percent sit loose, so the finder leaves them out.
| Band | Flat length x width, in | Stretch to wrap once |
|---|
Rubber band size chart
Standard size numbers with flat length and cut width. Circumference is twice the flat length, the distance around the band before it stretches.
| Size | Flat length x width, in | Circumference, in | Packrift |
|---|---|---|---|
| #8 | 7/8 x 1/16 | 1 3/4 | Stocked |
| #10 | 1 1/4 x 1/16 | 2 1/2 | Stocked |
| #11 | 1 1/2 x 1/16 | 3 | |
| #12 | 1 3/4 x 1/16 | 3 1/2 | Stocked |
| #14 | 2 x 1/16 | 4 | Stocked |
| #16 | 2 1/2 x 1/16 | 5 | Stocked |
| #17 | 2 3/4 x 1/16 | 5 1/2 | |
| #18 | 3 x 1/16 | 6 | Stocked |
| #19 | 3 1/2 x 1/16 | 7 | Stocked |
| #20 | 4 x 1/16 | 8 | |
| #22 | 5 x 1/16 | 10 | |
| #117A | 7 x 1/16 | 14 | |
| #27 | 1 1/4 x 1/8 | 2 1/2 | |
| #29 | 1 3/4 x 1/8 | 3 1/2 | |
| #30 | 2 x 1/8 | 4 | Stocked |
| #31 | 2 1/2 x 1/8 | 5 | Stocked |
| #32 | 3 x 1/8 | 6 | Stocked |
| #33 | 3 1/2 x 1/8 | 7 | Stocked |
| #35 | 4 1/2 x 1/8 | 9 | |
| #36 | 5 x 1/8 | 10 | |
| #38 | 6 x 1/8 | 12 | |
| #117B | 7 x 1/8 | 14 | Stocked |
| #142 | 8 1/2 x 1/8 | 17 | |
| #57 | 1 3/4 x 1/4 | 3 1/2 | |
| #61 | 2 x 1/4 | 4 | |
| #62 | 2 1/2 x 1/4 | 5 | Stocked |
| #63 | 3 x 1/4 | 6 | |
| #64 | 3 1/2 x 1/4 | 7 | Stocked |
| #69 | 6 x 1/4 | 12 | |
| #170 | 7 x 1/4 | 14 | |
| #172 | 8 1/2 x 1/4 | 17 | |
| #71 | 2 x 3/8 | 4 | |
| #72 | 2 1/2 x 3/8 | 5 | |
| #73 | 3 x 3/8 | 6 | |
| #74 | 3 1/2 x 3/8 | 7 | |
| #81 | 2 x 1/2 | 4 | |
| #82 | 2 1/2 x 1/2 | 5 | |
| #83 | 3 x 1/2 | 6 | |
| #84 | 3 1/2 x 1/2 | 7 | Stocked |
| #85 | 4 x 1/2 | 8 | |
| #105 | 5 x 5/8 | 10 | Stocked |
| #107 | 7 x 5/8 | 14 | |
| #92 | 2 1/2 x 3/4 | 5 | |
| #93 | 3 x 3/4 | 6 | |
| #94 | 3 1/2 x 3/4 | 7 |
How rubber band sizes work
- Flat length is the band pinched flat and measured end to end. It equals half the circumference.
- Cut width is how wide the strip of rubber is. A wider band holds tighter.
- Wall thickness decides how far a band stretches and how long it lasts: thin bands stretch further but snap more easily, and thicker bands are sturdier.
- The numbers run by width first, then by length within each width, so #14, #16 and #18 are the same width and get longer. Long bands carry three-digit numbers such as #105, #107 and #117B.
The most popular sizes and what they are for
- #64, 3 1/2 x 1/4 in: office paperwork, file folders and envelopes, mail bundles, kitting and order fulfillment. It meets postal requirements for bundling mail.
- #33, 3 1/2 x 1/8 in and #19, 3 1/2 x 1/16 in: the longest of the popular sizes, in the two narrow widths.
- #16 and #18, 2 1/2 and 3 x 1/16 in: the popular light bands.
- #32, 3 x 1/8 in: a general size the Postal Service also buys for its own use, along with #18 and #170.
How to measure a rubber band
- Pinch the two ends together and lay the band flat without stretching it.
- Measure end to end for the flat length.
- Measure across the strip for the cut width.
- Match both numbers to the chart; the size number follows.
Rubber bands by the case
Packrift stocks 16 standard sizes of brown rubber bands, from #8 to #117B, in cases of 550 to 34,000 bands, plus trash can bands and heavy-duty pallet bands. The rubber bands collection lists every case size and price.
Frequently asked questions
What do rubber band size numbers mean?
They identify width and length. Sizes are grouped by cut width, then numbered by flat length within each width, so #14, #16 and #18 are all 1/16 inch wide and get longer as the number rises.
What size is a #64 rubber band?
3 1/2 inches long, flat, by 1/4 inch wide, with a 7 inch circumference. It is the size most often called a standard rubber band.
What size is a #33 rubber band?
3 1/2 inches long, flat, by 1/8 inch wide.
What is the most common rubber band size?
#64 is the best known, and #16, #18, #19, #32 and #33 are the other most popular sizes.
How do you measure a rubber band?
Pinch the ends together, lay it flat and measure end to end for the flat length, then measure across the strip for the width.
What size rubber band for mail?
#64, 3 1/2 x 1/4 inch, which meets postal requirements for bundling mail.
Related tools and charts
Sizes from the Alliance Rubber Company size chart and size calculator, cross-checked against the federal rubber band specification A-A-131B. Popular sizes and uses as Alliance states them. Checked October 27, 2026.