A big question many pearl shoppers have is: What is the best pearl size to buy? We get it. Buying pearls online can be tricky … especially when you are not familiar with pearl sizing terminology.

This handy Pearl Size Guide will walk you through each major pearl type’s size range so you know what to expect. Also included is a helpful series of pictures of all our most popular Akoya pearl necklace sizes worn on a model. These images will help you determine which pearl necklace size is right for you.

Use the Table of Contents below to jump directly to any topic that interests you most, or read the entire guide.

Table of Contents:

Comparing Pearl Sizes

Akoya Pearl Sizes

Freshwater Pearl Sizes

Tahitian Pearl Sizes

South Sea Pearl Sizes

Popular Pearl Necklace Sizes on Model

Graduated vs Non-Graduated Necklaces

Cultured pearls are measured in millimeters. Akoya pearls are measured in half-millimeter sizes … Akoya pearl necklaces, bracelets, earrings and pendants will feature sizes like 6.0 - 6.5 mm, 6.5 – 7.0 mm, 7.0 – 7.5 mm and so on.

Tahitian, South Sea and Freshwater pearls are all measured in whole-millimeter increments. Earrings, pendants, rings will feature size listings like 10.0 – 11.0 mm, 11.0 – 12.0 mm, 12.0 – 13.0 mm and the like.

The image below shows the most popular Akoya pearl necklace sizes together in one place to give you an idea of how each half-millimeter size increase impacts the overall look of each pearl necklace size - and price.

As you can see, a half-millimeter increase doesn’t sound like a lot at first, but that extra volume can really add up. Each increase in size generally translates to about a 15-20% jump in size.

Akoya pearls are one of the smallest cultured pearl types and can range in size from tiny 1.0 mm seed pearls up through 9.5 mm, and rarely 10.0 mm at their largest. The most popular and common sizes are 6.0 – 6.5 mm up through 9.0 – 9.5 mm.

Other items that can be used to help visualize pearl sizes are a #2 pencil, which is 4.25 mm in diameter, so a 6.0 – 6.5 mm pearl will be slightly larger than a pencil eraser. A marble measures about 10.0 mm, so the largest 9.5 mm Akoya pearl earring will be slightly smaller than that.

The most popular Akoya pearl sizes for necklaces, bracelets and earrings are generally 6.5 - 7.0 mm, 7.0 – 7.5 mm and up through 8.0 – 8.5 mm.

📢 Read More: Akoya Pearl Buyer's Guide

Freshwater pearls are also a smaller size pearl type, but these pearls can get a bit bigger than the Akoya. The typical Freshwater pearl sizes range from small 2.0 mm seed pearls up through 11.0 – 12.0 mm, and even larger. For some of the newer Freshwater pearl types like the Edison or Souffle pearls, pearl sizes regularly reach 15.0 – 16.0 mm and even bigger than that.

The most popular Freshwater pearl sizes for necklaces, bracelets and earrings are generally 6.0 - 7.0 mm, 7.0 – 8.0 mm and 8.0 – 9.0mm.

📢 Read More: Freshwater Pearl Buyer's Guide

Tahitian pearls are one of the largest cultured pearl types available. Average pearl sizes range from 8.0 – 9.0 mm through 15.0 – 16.0 mm and sometimes larger.

The most popular pearl sizes range from 8.0 – 9.0 mm through 12.0 – 13.0mm especially for Tahitian pearl earrings, pendants and rings.

📢 Read More: Tahitian Pearl Buyer's Guide

White and Golden South Sea pearls are the largest cultured pearls in the world. Pearls range from 8.0 – 9.0 mm up through 16.0 – 17.0 mm, with some giants reaching up to 21 mm!

The most popular South Sea pearl pendant and earring sizes are 9.0 – 10.0 mm, 10.0 – 11.0 mm, 11.0 – 12.0 mm, 12.0 – 13.0 mm and 13.0 – 14.0 mm.

📢 Read More: South Sea Pearl Buyer's Guide

View our most popular pearl necklace sizes modeled for you:

Pearl necklaces are either “graduated” or “non-graduated”.

The graduation rate measures the increase in size of the pearls from the smallest sizes near the clasp to the largest pearls in the center.

Most “classic” Akoya and Freshwater pearl necklaces are “Non-Graduated”. This means that the pearls have no more than 1.0 mm size difference throughout the entire strand. So you’ll see measurements listed for the strands that look like 6.0 – 6.5 mm or 6.0 – 7.0 mm and the like. Graduated Akoya and Freshwater pearl necklaces are still available, but typically that is something that would need to be created by hand.

Graduated pearl necklaces like Tahitian and South Sea pearl necklaces, feature a graduation rate that can vary from 2.0 – 3.0 mm in size from the smallest pearls near the clasp to the largest pearls in the center. That is the average, there are many different variations within the “Graduated” pearl necklace category. Typical South Sea and Tahitian pearl necklace measurements will read something like 8.6 – 10.9 mm or 11.2 – 13.8 mm, for example.

Non-Graduated Tahitian and South Sea pearl necklaces exist, however they are much more expensive. The reason for that is that a Non-Graduated South Sea or Tahitian pearl necklace can take many years to create as farmers and sorters need to perfectly match pearls within a 1.0 mm sizes range for body color, overtone, luster, orient and surface quality in order to complete the strand.

• How To Buy Pearls
• Akoya Pearls 101 - Buying Guide
• Choosing Necklace Length