How To Use A Ring Sizer Belt

Written by: Benjamin Khordipour, Jewelry and Gemology Expert
February 21, 2024 – Posted in: Jewelry Blog

Ring sizer belts are an awesome way to check your size from home without traveling to a jeweler. This article will explain how to use the ring sizer properly to ensure you get the correct size.

Buy Now: Plastic ring sizer belt or metal ring sizing gauge.

The Guide to Using Ring Sizer Belt

ring sizer belt with customer and on finger size

Using the ring sizer belt is straightforward, but make sure that after you read the instructions, you also carefully read the tips and tricks below to avoid making mistakes.

  1. Clean your hand with room temperature water and then dry it properly
  2. Insert the ring sizer end into the buckle and tighten it around the finger you want to size
  3. Tighten until it is tight enough not to fall off your finger, but not so tight that it hurts.
  4. Extremely Important Step: Clench the finger while the ring sizer is on the finger. The ring sizer may adjust, and that is fine.
  5. Without loosening the belt, try to remove the ring sizer and ensure that it can easily slide over your knuckles.
  6. Ensure that you carefully read the number on the belt to ensure that you have calculated the correct number (or half number) the arrow is pointing towards.

Video Tutorial to Using the Ring Sizer Belt

Here’s the video we created on measuring your finger with our ring sizer belts.

How to Use the Ring Sizer to Measure your Finger Size?

As you can see in the video, sizing your finger with the ring sizing belt is very easy.

Warnings and Advice of Common Sizing Mistakes

Customer using the plastic ring sizer belt on ring finger

Sizing your finger with a ring sizer is extremely easy. The hard part is not making a few common mistakes while doing it.

Here are the most common mistakes that we see and how to avoid making them:

  1. Do not squeeze the ring sizer too tight onto your finger. If you squeeze too hard, you will get the wrong size, and you won’t even be able to fit it on your finger.
  2. Calculate the size for the correct thickness. The ring sizer has a width of 5mm, so if your ring has a width under 8mm, you should be fine with the measurement from the ring sizer. If, however, the ring band is thicker than 8mm, you will need to add a quarter size larger for every 3mm thicker of the band. So if your ring sizer says that you are a size 4.5 and you want to buy a ring with a band width of 11mm, you will need to ask your jeweler to size the ring to a size 5.
  3. Do not measure your fingers when you are sick, have swollen or cut fingers, are pregnant (unless you understand that you’ll need to change it later), or have moisturizer on your fingers.
  4. Consult with a jeweler if the ring sizer cannot slide over your knuckles without changing sizes. This is vital information to provide to the jeweler before sizing.

How to Read the Ring Sizer

reading the results on the ring sizer belt while on finger

Reading a plastic ring sizer can be tricky at first, especially when trying to discern the correct ring size amidst a series of closely spaced numbers. To accurately read the results, it’s essential to identify the full and half numbers marked on the sizer. Full numbers are indicated by whole integers (e.g., 6, 7, 8), while an un-numbered mark represents half numbers. Begin by locating the first number and mark on the ring sizer, then carefully count upwards until the mark that represents your size. By recognizing the sequence of numbers, you can ensure you’re not mistaking a half-size for a full-size or vice versa.

Once you’ve settled on a potential size, double-check by confirming the numbers immediately adjacent to your chosen size. This elimination method helps in accurately determining whether you’ve landed on a full or a half number by comparing it to the known markers around it.

Additional Techniques to Size Your Finger at Home

Customers using mandrel and ring edj sizing gauge

In addition to the ring sizer, you can measure a finger at home in a few other ways. Here are some of the alternatives.

  • Professional Ring Sizer Measuring Guage. A proper one costs approximately $10. This tool is a keychain with different-sized metal rings hanging from it. You can use it to test your finger until you find the best size. The advantage of this over the plastic ring sizer is that the metal rings better represent the sensation of the metal ring you plan on wearing.
  • Professional Jewelry Mandrel. A proper one costs approximately $15. A mandrel is a tapered rod that you can use to determine your ring size. You will slide an existing ring down the mandrel until it fits snugly, indicating its size on the marked scale. The advantage is that you can use the reference from an existing (well-fitting) ring. The disadvantage is that often you don’t have a good reference ring available. Another advantage is that the mandrel will be a good option for a surprise proposal.
  • Paper Printable Measuring Tool. These printable paper bands are available online for free, but be warned that most are inaccurate. We strongly caution our customers not to use these paper ring sizers.

Are Ring Sizers Accurate?

Plastic ring sizers are fairly accurate when countered against the possible schlep of going into a jewelry shop. They are definitely an improvement over the paper printable ring sizers or guesses from memory. They also enable easy online purchases. Just make sure that the jeweler offers a free extra sizing in case you end up with the wrong size.

Type of Ring SizerCostAccuracy Level
Plastic Ring Sizer Belt$275%
Professional Mandrel$1590%
Professional Metal Ring Guage $1095%
Paper Printable Ring SizerFree20%

How Professional Jewelers Measure Fingers

Benjamin from Estate Diamond Jewelry measuring the finger size of customers

Interestingly enough, most jewelers will use the same techniques listed above. The only difference, of course, is that the jeweler has so much more experience troubleshooting issues and knowing what to look out for.

When a customer visits a jewelry showroom to have their finger measured for a ring, the jeweler typically will begin by using a set of metal ring sizers. This initial fitting helps the jeweler determine a starting point for the ring size. It’s a simple yet effective method that allows for quick adjustments to be made based on the customer’s feedback, ensuring the ring chosen will be comfortable to wear daily.

Following this preliminary sizing, the jeweler might refine the measurement by using a cloth measure tape and examining the fingers to ensure that everything is in order.

If the jeweler sees the customer wearing a ring on the desired finger, he will likely also use a professional jeweler’s mandrel to double-check his numbers. This detailed measurement accounts for factors like knuckle size and the width of the desired ring, ensuring a precise fit.

Are You Looking for an Engagement Ring?

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Talk to a Jewelry Expert

Afshin and Benjamin Expert Jewelers at Estate Diamond Jewelry with customers and certifications

Do you have any questions about ring sizing, or are you looking for your engagement ring? Feel free to send us a message. We will respond within one business hour.