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How To Use A Ring Sizer Tool at Home

Ring sizer tools 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: Metal ring sizing gauge (Our Top Option)
How to Measure Your Finger at Home
When measuring your finger at home, you have several options—but not all are equally accurate. You can try wrapping a strip of paper or string around your finger and comparing the length to a sizing chart, or using a printable ring sizer, but these methods are often imprecise due to paper stretching or printer scaling issues. Plastic ring sizers offer a better alternative, but the most reliable and accurate option by far is a metal ring sizer—the same kind trusted by professional jewelers. Metal sizers provide consistent results, don’t warp over time, and give you the best chance of finding the perfect fit, especially for important rings like engagement or wedding bands.
Jump to: Metal Ring Sizer | Plastic Ring Sizer Belt
Option#1. Metal Ring Sizer Tool

A metal ring sizer tool is one of the most reliable ways to determine your correct ring size. It typically consists of a set of metal rings, each marked with a different size, strung together on a loop. To use it, simply slide the different sizes onto your finger until you find one that fits snugly but comfortably. The ideal size should go on with slight resistance over the knuckle and sit securely on your finger without feeling tight or loose. Make sure to test the fit at different times of the day, as finger size can fluctuate due to temperature and activity.
For the most accurate measurement, use the metal ring sizer on the hand and finger where you plan to wear the ring, especially if it’s for something like an engagement ring or wedding band. Avoid forcing a size that feels off—if you’re between sizes, it’s often best to go with the slightly larger one for comfort. Metal sizers are considered more accurate than plastic or paper alternatives, so jewelers often rely on them for professional fittings. If you’re unsure, consider visiting a jeweler who can double-check the fit using the same type of tool.
Buy metal ring sizer tool on Etsy.
Option #2. Plastic Ring Sizer Belt

Using the ring sizer belt is straightforward, but make sure that after you read the instructions to avoid making mistakes.
- Clean your hand with room temperature water and then dry it properly
- Insert the ring sizer end into the buckle and tighten it around the finger you want to size
- Tighten until it is tight enough not to fall off your finger, but not so tight that it hurts.
- Extremely Important Step: Clench the finger while the ring sizer is on the finger. The ring sizer may adjust, and that is fine.
- Without loosening the belt, try to remove the ring sizer and ensure that it can easily slide over your knuckles.
- 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.
Warnings and Advice of Using Plastic Ring Belt
That being said, the plastic ring sizer belt is NOT our preferred method to measure your finger from home. Our top option is the metal ring sizer tool.
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:
- 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.
- 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.
- 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.
- 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 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
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 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.
Which Ring Sizers are Most 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 Sizer | Cost | Accuracy Level |
Plastic Ring Sizer Belt | $8 | 65% |
Professional Mandrel (Needs Existing Ring) | $15 | 90% |
Metal Ring Sizer Tool | $12 | 95% |
Paper Printable Ring Sizer | Free | 20% |
How Professional Jewelers Measure Fingers
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.
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Talk to a Jewelry Expert
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.