Pearl size is usually measured in millimeters (mm), and can range from 1.0 mm to over 20.00 mm.

Pearl size is typically measured by its diameter in millimeters. While there are complications that come with measuring a round object, pearls have unique shapes that make them easier to measure.

For example, drop-shaped pearls are measured from the tip of the pearl to the point where it attaches to the pearl strand. On the other hand, baroque pearls have a more irregular shape and are measured by their longest diameter.

With the offset of baroque pearls, it is important to be aware that the size may not match up with an exact number.

Round-shaped pearls are also tricky to measure due to their roundness, but most jewelers use a device called a caliper to accurately measure the pearl’s diameter.

Calipers are used in measuring other round objects as well, such as coins and gemstones.

Pearl size is an important factor when it comes to both buying and selling, so it is important to know how to properly measure them according to their shape. With the right tools and knowledge, you can accurately measure pearl size and make sure that you purchase or sell the exact size that you need.

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Using a Caliper to Assess Pearl Size

The most common method to measure pearl size is to use a caliper, which is a device used to measure the distance between two points.

To measure the size of your pearl, simply place it inside the caliper, making sure that it is centered within the two points of the caliper. Then, read the measurement off the display to determine the size of your pearl in millimeters.

It’s also important to note that not all pearls are perfectly round; some may have an elongated shape or be more oval-shaped than round. In such cases, the measurement may be slightly different from what you expect.

Therefore, it’s important to measure multiple points on the pearl and take an average of all your readings to determine the most accurate size. With this method, you can easily measure pearls in millimeters so that you can find the perfect piece for your collection!

Precise Caliper for estimating Pearl Size in mm

Get this cool pearl size gauge from this Etsy Store. Alternatively, this precise caliper with a measuring gauge is a reasonable alternative.

A Ruler to assess pearl size

In addition to the caliper method, there are other ways to measure pearl size. For example, a ruler can be used to measure the diameter of a pearl.

The basic principle is to place the ruler along one side of the pearl and then measure from edge to edge. However, this method may not always be reliable due to potential discrepancies in the ruler’s measurement. Therefore, it’s best to use a caliper when measuring pearl size.

Expert size ranges for pearls.

Finally, jewelry experts also use terms such as “small”, “medium”, and “large” to describe the size of pearls. Small pearls are usually between 6-7 mm, medium-sized pearls are 8-9 mm, and large pearls are 10-20 mm.

Of course, these measurements are only a general guideline; some pearls may be slightly larger or smaller than the average size for their category.

Ultimately, it’s up to you to decide which pearl size fits best with your needs.

Variety of Pearl Sizes

Pearls come in a variety of shapes and sizes. Akoya pearls, one of the most traditional types of pearls, usually have round or near-round shapes and average 6-7 mm in size.

Freshwater pearls are slightly more irregular in shape but can range from 3 to 11mm in size.

Tahitian and South Sea pearls have larger ranges for their sizes, ranging from 8 to 20mm. Depending on the type of pearl you are looking for, there is sure to be something that fits your needs!


When it comes to purchasing pearls, it is important to understand how size affects the cost. Generally speaking, as the size increases, so does the price per pearl due to its rarity. Therefore, larger pearls tend to be more expensive than smaller ones.

As such, if you are looking for a specific size of pearl for your jewelry purchase, it is important to consider the cost before making a decision.

No matter what type or size of pearl you choose, make sure that it looks good and feels comfortable. After all, wearing a piece of jewelry is an expression of who you are!

So take your time when selecting the perfect pearl for yourself or someone special in your life. With so many options available, you can find something that accurately reflects your personal style.

About the Author


I am a pearl and oyster enthusiast who loves to share her knowledge and experiences about fashion with the world. I am neither a certified gemologist nor a reseller of pearls.

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