Because there are a variety of sizes and shapes to condoms, this is a general guide. Sometimes this will determine how you knit an amulet. There are so many knit designs yet to be explored--by you.
These are variations on the most familiar size, 2-1/4" x 2-1/4" squares.
Another square one--lights up in the dark--packaged in a 3" x 3" box.
From a dispensing machine (North Carolina, unisex rest room), the "Black Jack" measures 2" x 1-1/4". Just 50 cents but not latex.
Round condom, 2-1/4" circumference.
Lengthwise, smaller container,1/2" x 1" suited to this double-knitted amulet with beads to be worn around the neck. Or, it could have a pin back.
And the largest package contains the female condom, measuring 3-1/4" x 4-3/4". The condom itself is smaller, so the package can be folded up at bottom. It will then fit into an amulet like this one. Funky yarn here is a excellent re-use for yarn mistakenly purchased for a garment. Many possibilites for many gifts of Condom Amulets for friends, family. neighbors--room for several condoms too.
Its bright colors and loop make it easy to locate in a purse. Or, hang it on your bathroom wall--tuck the female condom behind a Post-It pad if discretion is a concern. Kay Gardiner, designer of the Ballband Key Chain Amulet, suggested this alternative use.