Getting the right ring size is essential — not just for comfort, but to make sure that beautiful ring actually stays on your finger. Too tight, and it’s painful. Too loose, and you risk losing it.
That’s why precise measurements are key. This article focuses on using millimeters (mm) for ring sizing. Millimeters provide a super-accurate way to measure, especially if you’re buying rings online or need to convert sizes internationally.
We’ll cover different methods for measuring your ring size, and share a ring sizing chart in mm to help you get a perfect fit.
Why Does Ring Size Matter?
An uncomfortable ring is no fun! Too tight, and it can hurt and even cut off your circulation. Too loose, and you risk losing it.
It’s also worth knowing that your fingers change size depending on the temperature, the time of day, and what you’re doing.
Getting an accurate size is especially important if you’re buying a ring made from a material like tungsten, which can’t be resized later.
Methods for Measuring Ring Size in Millimeters
If you’re buying a ring online, you’ll want to be sure you order the correct size. Here are a few ways to measure your ring size in millimeters:
Measuring an Existing Ring
- Inner Diameter Measurement: Use a ruler or calipers to measure the inner diameter of a ring that fits you well. Then, check your measurement against a ring size chart to find the corresponding ring size.
- Printable Ring Size Chart: Print a ring size chart and place your ring on the various circles to find the best match.
Measuring Your Finger Directly
- String or Paper Strip Method: Wrap a thin strip of paper or string around the base of your finger, mark where the ends meet, and measure the length in millimeters. Then, check your measurement against a ring size chart to find the corresponding ring size.
- Ring Sizer: You can buy a set of graduated ring sizers that allow you to test different sizes on your finger until you find one that fits comfortably.
Understanding the Ring Size Chart in Millimeters
A ring size chart is handy when you’re trying to figure out your ring size in either U.S. sizes or millimeters. Here’s what you need to know about reading one.
Key components of a ring size chart
- U.S. ring size: Most ring charts use the standard U.S. ring size system, numbered in half sizes.
- Inner diameter (mm): The inner diameter is the measurement across the inside of the ring. If you measure 16.51 mm across the inside of one of your rings, for example, your ring size is likely a U.S. size 6.
- Circumference (mm): The circumference is the distance around the inside of the ring. This is less common for direct measurement, but it can be helpful for confirming your size.
Using the chart for conversions
A ring size chart can help you convert from U.S. sizes to millimeters and vice versa.
- Converting from U.S. size to millimeters: Look up your U.S. ring size on the chart to find the corresponding inner diameter in millimeters.
- Converting from millimeters to U.S. size: Measure the inner diameter of a ring that fits you well, and then use the chart to find the corresponding U.S. ring size.
What affects ring size?
It’s important to remember that several things can change your ring size.
- Temperature and Time of Day: Your fingers may swell in heat or shrink in cold. Measure your fingers when they’re at room temperature and at different times of the day for the most accurate results.
- Knuckle Size: If your knuckle is significantly larger than the base of your finger, choose a size that fits comfortably over your knuckle but isn’t too loose on the base of your finger.
- Band Width: Wider bands tend to fit more snugly. You may need to go up half a size for wider bands.
- Swelling: Avoid measuring your fingers after a workout or any activity that causes them to swell.
Key Takeaways
Getting the right ring size is crucial for comfort and how the ring looks on your finger. A ring that’s too tight is uncomfortable, and a ring that’s too loose can easily slip off and get lost.
You can measure your ring size in millimeters using several methods, including ring sizers, printable charts, and measurements from an existing ring.
To find the perfect fit, use a ring sizing chart and think about things like the width of the band and how your finger size can change.