What Is the Smallest Ring Size?

All brides are different, and so are their fingers, and finger-sizes. Often, brides with small fingers are extremely concerned about finding the correct ring size. In this guide, Benjamin Khordipour, will explain what the smallest official ring size is and proper tips for measuring small fingers correctly.

What’s the Smallest Ring Size?

The official smallest ring size for adults in the United States of America is US size 3 (which measures at ~14.1 mm). For children jewelry in America, the size can go down as low as US size 1-2, but children’s jewelry is almost never “fine-jewelry”.

That being said, if you have very small fingers, you can always custom commission handcrafted jewelry in any size, even in sizes far smaller than US size 1.

How Small can an Engagement Ring be Resized?

Although you can technically resize any ring to any size, resizing an engagement ring (especially an intricate one) down to a size lower than US size 4 is usually an incredible challenge.

The reason resizing down under US size 4 is so difficult is because once the band becomes so small the curvature of the ring also sharpens. This requires the jeweler to make extreme efforts to adjust the entire ring (and gemstones) to match the new dimensions.

“It is usually easier for us to remake the ring from scratch then to resize the ring to a size lower than US size 4,” says Afshin Shaddaie.

What Is Considered a Small Finger Size? 

Generally speaking, any finger under US size 5 is considered small. The size US 5 measures 49 millimeters in circumference or 15.6 millimeters in diameter. This doesn’t mean that brides with a small finger size will have trouble finding a ring, though. 

The average women’s ring size is US 6, followed by US 5. Petite women tend to have more slender fingers. Thus, most jewelry stores strive to carry a wide selection of small engagement rings.

That being said, the availability of rings sized under US Size 4 is scarce. Usually for sizes under size 4, they will need to be custom commissioned.

Smallest US Ring Size 

Although size sticks and other ring size measuring tools start with size US 1, the smallest ring size in the US is 3. It’s considered extra small and measures 44 millimeters in circumference or 14 millimeters in diameter. 

The next smallest finger size is US 4, measuring 46.5 millimeters in circumference or 14.8 in diameter. And unlike the ring size US 3, size US 5 is quite common and measures 49 millimeters in circumference and 15.6 in diameter. Half sizes are also available. 

Smallest UK Ring Size 

Ring sizes in the United Kingdom are measured alphabetically, and so the smallest official ring size is UK F (which is a circumference of 44.20mm). The finger sizing starts with UK A (which is a 37.8 millimeters circumference), but most jewelry stores will have their smallest ring starting as UK size F.

Like the US system, all rings can be custom-commissioned to any size.

How to Measure the Ring Size for a Small Finger

Smaller fingers are tougher to measure than larger fingers, especially with the traditional plastic ring sizers shown above. It is for that reason, that we recommend using a metal ring sizer kit, as shown below.

To use this ring sizer, you need to place your finger inside each ring and see which one fits your finger best. The ring sizer will typically starts at size 0, and so it should cover any finger size, even very smaller fingers.

If the ring on the ring sizer tool is too tight, the ring will also be too tight.

Please note that if you’re planning on buying a ring that is very wide, you may need to factor that your ring size will need to be half a size or so larger. Consult with your jeweler regarding this.

This ring sizer is the same tool that professional jewelers use and it is available for purchase under $15. Here’s a link to buy it at Etsy.

Talk to an Expert Jeweler

Have questions about small engagement rings? Fill out the form below. One of the experts at Estate Diamond Jewelry will respond within one business hour.