How to Measure Mason Jar Sizes Accurately

Mason jars are important due to their ability to preserve and store food safely. The jars have a durable design that can keep many food items secure in them. The jar has a two-part, threaded lid that develops an airtight seal to ensure proper canning and freshness occurs of the food stored in the jar. People use the jars for meal prep as well as fermentation. They are reusable also. It is important to get the right mason jar specifications if you want to ensure the jar securely and effectively stores and preserves the food product.

Importance of getting right mason jar size

Businesses and individuals who use mason jars need to ensure the size of the jar is right for what needs to be stored in it. The following explains why mason jar size is important:

•     Food safety: The right jar size will ensure proper heat distribution will occur that can kill bacteria. If you opt for a jar which is really large, this can result in under-processing.


•     Follow recipe: Canning recipes get made for certain sizes. Employing smaller jars can be safe, however using bigger jars than needed can lead to spoilage.


•     Headspace control: The correct size jar lets there be the right amount of headspace present. Headspace refers to the gap present between the food along with the lid. This is necessary for developing a proper vacuum seal.


•     Less waste: If you use the correct size jar, waste will be limited, because the contents may be consumed quickly.


•     Functional: The right jar size will be usable and functional. It will be simple to fill it and pour out the contents.

If you want to get the right mason jar size, you need to keep some points in mind. The following discusses how to measure mason jar size properly:

Mouth diameter

It is necessary to know the mouth diameter as this helps with lid compatibility. There are two types available:

•     Regular Mouth: This has around 2 ⅜ inches or 60 mm inner diameter. It may have 2.75 inches outer. The jar can be used for pourable liquids, like syrups, sauces, juices, etc.


•     Wide Mouth: This has around 3 inches or 76 mm inner diameter. It may have 3.38 inches outer. This one is better for chunky and solid foods such as pickles, peaches, layered salads, etc. The jar is simpler to fill and even clean by hand.

If you want to place the jar in the freezer, you can consider straight-sided jars without shoulders. These let expansion occur without shattering.

Common size jars

The following table looks at the common jar sizes and what they can be used for:

According to what you need to store, you can choose which jar size will be suitable. The wrong jar size can lead to broken jars and even unsafe food.

Tips to measure:

The following points can be kept in mind when measuring to get accurate measurements:

•     Look at embossing: Some manufacturers emboss the capacity at the bottom area of the jar.


•     Ruler or tape measure: You can use a ruler or tape measure to measure straight across the opening. This will help you know if the jar is a regular or wide mouth one.


•     Test: You can test the jar by filling it with water. Pour this water into a measuring cup. This will help you know the exact capacity.

There are a variety of mason jar sizes available in the market. It is important to choose the correct size jar if you want to ensure the food is protected and preserved effectively.

If you want to get high-quality mason jars, contact EZ Custom Boxes.

EZ Custom Boxes gives clients:

•     Durable packaging materials


•     The right specification mason jar


•     Wholesale packaging

Contact Details:

•     Email: [email protected]


•     Phone: +1-888-515-1263

Frequently Asked Questions (FAQs)

How to measure mason jar sizes properly?

To get the right measurements, you need to identify the mouth diameter and see if it is a regular or wide mouth jar. Determine the volume you require and get a jar that can suit this.

Why should you avoid getting the wrong size mason jar?

The wrong size mason jar can result in seal failures, limited shelf life, and dangerous glass breakage when processing is happening. You will end up wasting money getting a jar like this.

Why are mason jar sizes important?

Mason jar sizes are important as they ensure proper heat distribution will occur which can kill bacteria. The right size jar will help one adhere to the recipe. There can be less wastage of food when you get the right jar.