If Mason jar sizes confuse you, you’re not alone! One of our top FAQs is about jar mouth sizes—and we’ve got you covered. 🫙 How to check your jar size: Measure straight across the mouth, edge to edge. Regular Mouth ➡️ 2 3/4 in (7 cm) Wide Mouth ➡️ 3 3/8 in (8.6 cm) Whether you’re buying new jars or finally putting your stash to use, this quick tip makes finding the right lids & accessories so much easier. 👉 Most of our Masontops tools come in both - regular and wide size, so make sure to choos