Decoding Pearl Sizes and Finding Your Perfect Fit

Pearls, the organic gems from the sea, have captivated us for centuries. But did you know that the size of the pearl plays a huge role in its beauty, value, and how it’s used in jewellery?

From tiny seed pearls to magnificent South Sea giants, the world of pearl sizes is diverse. This guide will help you understand everything you need to know to choose the perfect pearls for you!

Table of Contents

• 1. Measuring Up: How Pearls are Sized
• 2. Different Pearl Types and Their Typical Sizes
• 3. The Bigger, the Pricier? Understanding Size and Value
• 4. Finding Your Perfect Fit: Choosing the Right Pearl Size

1. Measuring Up: How Pearls are Sized

Unlike diamonds, which are measured in carats, pearls are measured in millimetres (mm), referring to their diameter. Even one millimetre can dramatically change a pearl’s appearance and price.

Jewellers use a special tool called a pearl gauge for precise measurements.

For round pearls, the diameter is measured. For other shapes, like drops or baroque pearls, both the shortest and longest sides are often measured (e.g., a drop pearl might be described as 10 × 14 mm).

Sizing conventions: Strands are commonly sold in half-millimetre ranges (e.g., 7.0–7.5 mm). Diameters are usually rounded to the nearest 0.5 mm. For non-round shapes, sizes are written height × width.

2. Different Pearl Types and Their Typical Sizes

Each type of pearl has its own typical size range. Let’s explore the most popular ones:

Akoya pearls (2–10 mm)

These classic white pearls, mainly from Japan, shine with brilliant lustre. They typically range from 2–10 mm, with 6–8 mm being the most common. Pearls larger than 8 mm are quite rare for Akoya pearls.

Freshwater pearls (2–15 mm+)

These pearls come in many shapes and sizes. They range from tiny 2 mm seed pearls to large 15 mm or bigger.

Tahitian pearls (8–14 mm)

These exotic dark beauties from French Polynesia are larger, usually ranging from 8–14 mm. Some pearls can even reach 16 mm or more!

South Sea pearls (9–20 mm)

The “Queen of Pearls”, South Sea pearls are the largest of all. They typically range from 9–20 mm, with an average of 12–14 mm. These are true statement pieces.

Seed pearls (under 2 mm)

These tiny pearls are usually under 2 mm in size and are used for intricate embroidery or delicate jewellery designs.

A Pearl Size Chart

Here is a chart comparing different pearl types and their common sizes, with real-life objects for scale.

Pearl size (mm)	Akoya	Freshwater	Tahitian	South Sea	Mabé	Seed	Real-life object
1–2						X	Poppy seed
2–3	Rare	X					Small peppercorn
3–4	X	X					Tip of a new crayon
4–5	X	X					Small BB pellet
5–6	X	X					Green pea
6–7	X	X			X		Pencil eraser
7–8	X	X			X		Small blueberry
8–9	X	X	X		X
9–10	X	X	X	X	X		Chickpea
10–11	Rare	X	X	X	X		Small marble
11–12		X	X	X	X		Small grape
12–13		X	X	X	X		Large blueberry
13–14		X	X	X	X		Hazelnut
14–15		X	Rare	X	X		Cherry
15–16		X	Rare	X	X		Small strawberry
16–20		Rare	Rare	X	X		Large grape / gumball
20+		Rare	Rare	Rare	X		Larger than a gumball

*Mabé (blister) pearls are dome-shaped and commonly used for earrings and pendants; sizes refer to the dome diameter (often 10–20+ mm). Real-life object comparisons are approximate and for scale only.

3. The Bigger, the Pricier? Understanding Size and Value

Larger pearls usually cost more, assuming other quality factors are equal. This is because they take more time to grow, there’s a higher risk the mollusc may not survive, and therefore bigger pearls are simply rarer. An 8 mm Akoya pearl will cost significantly more than a 6 mm Akoya of the same quality.

Price examples by size

Note: These are illustrative ranges. Final prices depend on lustre, surface quality, shape, nacre thickness, and matching, in addition to size. Grading labels (AA/AAA) can vary by seller.

Akoya pearls (AAA-grade strand)

• 6.0–6.5 mm: $800 – $1,500
• 8.0–8.5 mm: $3,000 – $6,000

South Sea pearls (AA-grade single pearl)

• 9–10 mm: $400 – $800
• 13–14 mm: $1,500 – $3,500

Freshwater pearls (AA-grade strand)

• 6–7 mm: $50 – $150
• 10–11 mm: $200 – $500

Key takeaways on price:

• Size and price are directly related: As size increases, the price increases—often exponentially.
• Pearl type matters: South Sea pearls are typically the most expensive, followed by Tahitian and Akoya, with Freshwater pearls being the most accessible.

4. Finding Your Perfect Fit: Choosing the Right Pearl Size

So, how do you actually choose the right pearl size for you or for a gift? Here are the key factors to consider:

• Your budget: Start with a comfortable budget, which will help guide you to the right pearl type and size range.
• Personal style: Do you prefer delicate, understated jewellery or bold, statement pieces?
• Jewellery type: The ideal size for stud earrings (typically 6–8 mm) is very different from a statement pendant (often 10 mm+).
• Occasion: Are you looking for an everyday piece or something for a special event?
• Your features: Consider your own proportions, like your earlobe size for studs or your neckline for necklaces.

To read in detail about these 5 points, refer to our blog on 5 quick & easy ways to find the perfect pearl size for you.

Conclusion

From dainty seed pearls to impressive South Sea giants, the world of pearl sizes is full of possibilities. Understanding how to measure pearls and how size impacts value will help you make informed decisions when you buy.

Ultimately, the perfect pearl size is the one that you love and that makes you feel beautiful and confident!

What’s your favourite pearl size? Let us know in the comments!