Understanding Mason Jar Mouth Sizes


If you're confused about Mason jar sizes, know that you're not alone! Our top product-related question is always about Mason jar mouth sizes. To make shopping a little easier, we've put together this handy guide to determine what size mouth your Mason jars have with links to their corresponding Masontops products.

The most important thing to remember is brand, volume and height have nothing to do with determining mouth size. All you need to look at is the diameter across the mouth of the Mason jar, edge to edge. 

Regular Mouth 2.75 in / 7 cm
Wide Mouth 3.38 in / 8.6 cm

Buying New Mason Jars?

If you're buying new Mason jars and aren't sure which size to get, we highly recommend wide mouth Mason jars. They usually come in larger volume sizes and are more popular, which means there are better accessory and lid options. Masontops makes products in both regular and wide mouth sizes, but we have some products–like the Complete Fermentation Kit and Coffee Caps–available for wide mouth Mason jars only. 

Masontops now makes our own Mason jars! Get 4x 24oz Wide Mouth Mason jars with 4x Tough Band plastic screw bands, 4x Chalk Top blackboard lids, 1x Top Chalk erasable chalk marker all in one pack. These jars are great for fermenting and the included Tough Bands will never rust or warp. Once you're ferment is done, label it with a Chalk Top disc lid and store it in the fridge. 

Before you buy your Mason jars, read this article to determine which type of Mason jar is right for you and what brands to buy from.