Size charts
Pearl size chart: actual sizes in mm
Pearls are measured by diameter in millimeters. GIA gives typical ranges of under 9 mm for Akoya pearls, 8 to 14 mm for Tahitian pearls and 8 to 18 mm for South Sea pearls. Freshwater pearls run from about 4 to 12 mm in dealers' guides. Most white pearl strands sold today measure 7 to 8 mm.
Data checked October 20, 2026 against the sources listed below.
Pearl sizes by type
Pearl sizes by type
| Pearl type | Typical size (GIA) | Range in dealers' guides | Most common sizes |
|---|---|---|---|
| Akoya | Under 9 mm | 2 to 9.5 mm, rarely up to 10.5 mm | 7 to 8 mm |
| Freshwater | Mostly smaller sizes (GIA gives no mm range) | 4 to 12 mm | 7 to 9 mm (6 to 11 mm in some guides) |
| Tahitian | 8 to 14 mm | 8 to 16 mm; Stuller reports rare pearls up to 20 mm | 9 to 11 mm (9 to 13 mm in some guides) |
| South Sea | 8 to 18 mm | 8 to 20 mm; most are 10 to 15 mm | 10 to 12 mm (9 to 14 mm in some guides) |
Pearl sizes in mm and inches
| Diameter (mm) | Inches |
|---|---|
| 3 | 0.12 |
| 4 | 0.16 |
| 5 | 0.20 |
| 6 | 0.24 |
| 7 | 0.28 |
| 8 | 0.31 |
| 9 | 0.35 |
| 10 | 0.39 |
| 12 | 0.47 |
| 14 | 0.55 |
| 16 | 0.63 |
Which pearls come in each size
| Size | Pearl types you will find |
|---|---|
| Under 6 mm | Akoya, freshwater |
| 6 to 7 mm | Akoya, freshwater |
| 7 to 8 mm | Akoya, freshwater |
| 8 to 9 mm | Akoya (top of its range), freshwater, Tahitian, South Sea |
| 9 to 10 mm | Freshwater, Tahitian, South Sea; Akoya is rare |
| 10 to 12 mm | Tahitian, South Sea, larger freshwater |
| 12 to 14 mm | Tahitian, South Sea; freshwater is rare |
| Over 14 mm | South Sea; Tahitian is rare |
How pearl strands are sized
| Pearl type | Size steps | Example |
|---|---|---|
| Akoya | A 0.5 mm range per strand | 7.0-7.5 mm |
| Freshwater | Usually full millimeters; finer strands use 0.5 mm steps | 7-8 mm, or 7.5-8 mm |
How to measure
- 1
Measure across the pearl
Pearl size is the diameter in millimeters. A caliper or a millimeter gauge gives the most accurate reading.
- 2
Read a strand's size range
A strand is sold by the range its pearls fall in, such as 7.0-7.5 mm for Akoya. A graduated strand gets larger toward the center, so its range is wider, such as 8-10 mm.
- 3
Compare with the circles
Print this page at 100% scale, check the 50 mm bar with a ruler, then lay a pearl over the circles to read its size.
Why half a millimeter matters
A pearl's face-up area grows with the square of its diameter and its volume with the cube. Going from 7.0 to 7.5 mm makes a pearl about 15% larger face-up and about 23% larger in volume.
Frequently asked questions
For white pearl strands, 7 to 8 mm. Most Akoya necklaces sold today fall in this range.
About 0.31 inches across, just over 5/16 of an inch. It sits near the top of the Akoya range and at the small end of the Tahitian and South Sea ranges.
South Sea pearls. GIA gives a typical range of 8 to 18 mm, and the largest reach about 20 mm.
Not as a rule. Dealers' guides put freshwater pearls at about 4 to 12 mm, which covers the whole Akoya range and goes larger.
By diameter in millimeters. Akoya strands are sold in half-millimeter ranges such as 7.0-7.5 mm, and freshwater strands often in full millimeters such as 7-8 mm.
About 0.39 inches across. Ten millimeters is above the usual Akoya range and inside the most common sizes for Tahitian and South Sea pearls.
Use this chart on your site or listing
Free to embed or print, as long as the credit link to Hues AI stays with it. Copy the code:
Sources
Related charts & tools
See it worn: Virtual necklace try-on
Lifelike on-model necklace imagery in about 30 seconds.
See it worn: Earring virtual try-on
On your own ear or on a model: studs, hoops and drops in about 30 seconds.
Necklace length chart
Necklace length chart from 14 to 36 inches with cm: where each length sits, men's chain lengths, a cm-to-inch table for metric chains and how to measure.
Earring size chart
Earring size chart: diamond stud sizes from 3 mm to 10 mm with carat weights, hoop earring sizes from huggies to oversized, and drop earring lengths.
Bracelet size chart
Add about 0.5 in (1.3 cm) to your wrist for a comfortable bracelet. Wrist-to-length chart in inches and cm, a cm-to-inch table and bangle sizes in mm.
Selling the pieces in this chart?
Hues turns one photo of your piece into catalog shots, on-model images and product video for your store. Start with 80 free credits, no card required.