Ring Size Chart: How To Choose the Perfect Ring Size

So you’ve decided on an engagement ring that suits you and your beloved. There’s no reason you can’t get the ring size perfectly correct.

But you have to know a reliable way to determine the ring size, including using an ring size chart, together with other reliable methods for determining ring size.

After all, you’ve picked out the perfect diamond. You’ve selected a setting that fits your beloved’s style — and lifestyle. When you pop the question, you want there to be no question that it will fit.

This article, armed with strategies and a ring size chart, will guide you to a 100% certain outcome: the perfectly sized ring.

Ring Size Chart

Inside Circumference (mm)Inside Diameter (mm)US Ring Size

Don’t Let These Engagement Ring Size Nightmares Happen to You

  • Too tight! The ring can’t fit onto your beloved’s finger.
  • Too loose! The ring goes on, but it’s too loose. It’s in danger of falling off.

But Here’s the Good News

Even in a best-case scenario, an ill-fitting ring can be disappointing.

And best of all, you can easily get the ring size the first time, without guessing.

I’ll show you how.

Now Imagine This Success, Which I’ll Show You Exactly How to Reach

  • Just right! You did your homework to determine her ring size with scientific precision — and it fits perfectly.

In this blog, we’ll dispel some common sometimes unreliable methods of determining ring size. Then we’ll spell out for you two scientifically precise ways you can get it right — both of which can be complemented by the other methods.

The Importance of Determining the Correct Ring Size

Some rings cannot be resized. Or else it’s very difficult and risky. These include most rings with pavé and channel settings, and rings with diamonds around the entire band.

Why not avoid this potentially massive headache by getting the ring size correct your first time around?

How to Use a Piece of String or Paper to Measure Ring Size

Here’s how to use string or paper, a pair of scissors, a sharp pen, and the ring size chart below, in order to determine the perfect ring size.

It can be a little tricky. But it’s completely doable.

You can reduce the chance of errors or inaccuracies to almost zero by taking the following precautions:

  1. Use a very sharp pen, so that the mark on the paper or string is sharp and clear. I can recommend this model. The mark it leaves is precise and dark. https://www.amazon.com/Pilot-Precise-Precision-Ink-5mm-35334/dp/B00006IEBI
  2. Use large diameter cotton string if using string. This is an excellent choice. https://www.amazon.com/Norpro-942-Cotton-Twine/dp/B000ST1EW6
  3. Use a strip of paper no wider than about 4mm, if using paper. The smaller the width of paper, the more accurate the measurement will be. Cut several identical strips of paper, for multiple measurements.
  4. Measure her finger at least three times, with at least three different pieces of string or paper. If the resulting observations of measurement differ at all, keep measuring until you get a consistent observation at least three times in a row.
  5. If using string, be very careful to not make it too tight around her finger. String is narrow, and can push down into a finger, and make the ring size appear smaller than would actually fit.
  6. Consult the chart we provide on this page. Match the measurement you took of the string or paper to the “Inside Circumference” on the chart. Voila, you have her ring size.

Following the precautions and tips above when measuring for ring size with string or paper, you’ll reduce the chance for error to almost zero.

Why Asking a Jeweler to Measure Ring Size May Be Unnecessary

Asking a local jeweler to determine ring size is a reliable way to get an accurate measurement.

And yet, you can easily do everything the jeweler can do, with the right tools.

It’s not hard or expensive.

Also, remember that more and more people are buying engagement rings online, and for very good reason.

In brick and mortar stores, the selection is often limited compared to the vast inventories at James Allen, Blue Nile, or Brian Gavin.

Another issue is a social one — perceived obligation after receiving a favor such as a complimentary ring sizing. It could be a little awkward, if there’s a possibility that you’ll shop online after all.

Plus, with the right tools, you can do it on your own.

I explain how you can quickly and inexpensively obtain and use two professional tools to do just that, just a little further down in this article.

How to Estimate Ring Size With a Bar of Soap

With the bar of soap method, you do the following:

  1. Impress into a bar of soap a ring which is known to fit perfectly your beloved’s finger.
  2. Carefully pry it out.
  3. Measure the diameter of the resulting impression and use a ring sizing chart to determine the correct size. (On the chart included on this page, you’d match that measurement to the “Inside Diameter in Millimeters” column.)

This method can work if you’re careful. And it’s probably best to make up to three impressions, measure each one, to make sure that the measurements are accurate.

This method takes some risks with accuracy since the impression may waffle a bit, either when the ring is being pressed in or pulled out. But if you’re careful, it can work.

Reliable Ways to Determine Ring Size With Professional Tools

To be 100% sure of getting the ring size right, you can choose a professional method which is surprisingly easy and available to anyone.

The tools are inexpensive and easy to obtain online.

There are two ways, actually — each with its own tool.

If the Proposal Is Not Meant to Be a Surprise, Use This Tool

This stainless steel ring sizer is what a jeweler would use to determine the ring size. 

If the planned proposal is not a surprise, then you can use this ring sizing set. Together with your beloved’s participation, you can easily determine her ring size.

It’s important to choose a ring sizing set which includes full, half, and quarter sizes, just in case her ring size falls on a quarter inch measurement.

This professional tool only looks “expensive” at $20. However, do notice:

  • You’re not paying for the tool. You’re paying $20 to be remembered, for a lifetime, as having got this right.
  • You need a ring sizer which includes full, half, and quarter sizes. Not just full or half sizes.
  • You can probably find an equivalent set elsewhere, for less. I linked to this one because it’s in stock and it’s professional. Just be sure to get one that is stainless steel, and that includes full, half, and quarter sizes.
  • We don’t recommend using a plastic version. The stainless steel variety is a professional tool, and the expense is not prohibitively high.

If You’re Determining Her Ring Size Secretly

If you’re determining her ring size secretly, then get one of these.

With a professional ring sizing mandrel, determining her ring size is easy. Here’s how to do it:

  1. Hide the mandrel in your clothing, or laptop bag, etc.
  2. Gain access to a ring of hers which you know to fit her perfectly well
  3. Slip it secretly over the mandrel.
  4. Take a picture of it on the mandrel with your phone so you’ll be sure to remember the exact measurement.
  5. Return the ring.

How to Use a “Circle” Ring Size Chart to Determine the Perfect Ring Size

A ring size chart can be useful if you don’t have the time to obtain professional tools.

As long as you’re careful, and follow the instructions in a reliable ring diameter sizing chart, you’ll be able to determine the ring size with a high degree of accuracy. (See the one we provide on this page — or use this high tech version of such a chart at James Allen. https://www.jamesallen.com/ring-sizer/measure-ring/) 

It’s quite simple and direct. Best of all, it can be done right away.

  1. You place a ring which is known to fit her finger on possible corresponding circles of the ring size chart. (Or of course follow the instructions at this high tech version at James Allen.) https://www.jamesallen.com/ring-sizer/measure-ring/
  2. The circle on the ring chart which best fits the ring is the correct size.

Final Thoughts

To sum up, you can use any or more than one of the following methods for finding the correct ring size, so that you can go on to choose and order the perfect engagement ring.

  1. Paper and scissors, or string and scissors.
  2. Soap impression.
  3. Professional ring-sizing tools ordered online.
  4. A reliable ring sizing chart. (There’s one provided on this page.)

Questions or comments? Contact Us

If you have any questions or need help, guidance or just want someone to talk through anything having to do with selecting the perfect engagement ring, contact us. We stand ready to help you with any part of your engagement ring selection experience.