With so many different Mason jar sizes and manufacturers, it can be difficult to know what size Mason jar you have or what size Mason jar lid will fit your jar.
Mason Jar Mouth Size – The diameter of the Mason jar opening determines the mouth size. Choose from either regular or wide mouth sizes.
reCAP Pour Cap Size
You can also determine the size of your reCAP by comparing it to the length of a standard credit card. A regular sized reCAP Mason jar lids diameter is smaller than the length of the credit card, however, a wide-mouth reCAP is just slightly larger.