Eternity Ring Sizing Guide: Get the Fit Right

An eternity ring is a forever kind of gift—but getting the wrong size can make it anything but romantic. Because of their full-circle design, many eternity rings can’t be resized, making accurate sizing absolutely essential. Whether you’re buying one as a gift or for yourself, this guide will walk you through how eternity rings should fit, how to measure properly, and what to do if resizing isn’t an option.

Why Sizing Matters More with Eternity Rings

Full Eternity Rings

• Cannot be resized due to diamonds wrapping the entire band

• Even minor sizing changes would disrupt the stone layout or setting integrity

 Half Eternity Rings

• Can usually be resized, as the bottom of the ring is plain metal

• Still, frequent resizing should be avoided to preserve band strength
  

How Should an Eternity Ring Fit?

• Snug—but not tight: Should slide over the knuckle with slight resistance

• No spinning: Especially important with half eternity rings

• Comfortable for stacking: If pairing with engagement/wedding ring, ensure proper width and fit

Tip: Eternity rings often feel tighter than plain bands due to added thickness and diamond edges.

How to Measure Ring Size Accurately

Best Method: In-Person Professional Sizing

• Visit a trusted jeweler and request sizing with a comfort-fit band

• Try multiple widths (eternity rings are often 2–4mm wide)

• Account for finger swelling (measure at midday)

Buying Online? Try These:

• Order a ring sizer: A plastic tool or sizing belt gives accurate results

• Use an existing ring: Measure the inside diameter and compare to a size chart

• Downloadable sizing guides: Less accurate but helpful in a pinch

Never measure with string—it’s too stretchy and often inaccurate.

Ring Sizing Tips to Consider

What If You Get the Size Wrong?

For Full Eternity Rings:

• Return & reorder: Many jewelers offer 30-day return or remake policies

• Ask about “stone substitution” options: Some custom jewelers will recreate with the same stones

For Half Eternity Rings:

• Resizing range is usually +/- one size

• More than that may weaken prongs or misalign diamonds

Pro Tip: Consider Ring Width

The wider the band, the tighter the ring will feel.

• A 2mm band may feel looser than a 4mm eternity ring of the same size

• If stacking, make sure combined width doesn’t cause tightness

​Eternity rings represent forever—so it’s worth spending a few extra minutes getting the fit just right. By planning ahead and measuring carefully, you’ll avoid returns, discomfort, and resizing issues—and ensure that the moment you slip it on is just as perfect as the love it symbolizes.