Ring Sizer Online
Are you shopping for a ring but unsure about your size?
Whether you’re buying an engagement ring, a fashion ring, or a special gift, getting the right ring size is crucial for comfort and fit.
In this comprehensive guide, we’ll show you two foolproof methods to measure your ring size at home, complete with an interactive ring size calculator and detailed size charts.
Understanding Ring Sizing Methods
There are two reliable methods to determine your ring size at home:
- The Thread Method: Using string or paper to measure your finger’s circumference
- The Existing Ring Method: Measuring a ring that already fits you perfectly
Our interactive calculator below supports both methods, making it easy to find your exact ring size in US measurements.
Ring Size Calculator
Method 1: The Thread Method (String or Paper Measurement)
What You’ll Need
- A piece of string, floss, or strip of paper
- A ruler with millimeter measurements
- A pen (if using paper)
Step-by-Step Instructions
Choose Your Material
- Dental floss or string works best as it’s flexible yet sturdy
- If using paper, cut a thin strip about 1/4 inch wide
Prepare Your Finger
- Measure at the end of the day when your fingers are at their largest
- Ensure your hands aren’t cold (cold fingers can be up to 1/2 size smaller)
- Remove any rings from the finger you’re measuring
Take the Measurement
- Wrap the string/paper around the base of your finger
- Mark where the string/paper overlaps
- Make sure it’s snug but not tight
- For paper, mark the overlap point with a pen
Measure the Length
- Lay the string/paper flat against a ruler
- Measure the length in millimeters
- Use our calculator above or consult the chart below
Thread Method (Circumference Measurement)
| Measurement (mm) | US Ring Size |
|---|---|
| 44.3 | 3 |
| 44.9 | 3.25 |
| 45.5 | 3.5 |
| 46.2 | 3.75 |
| 46.8 | 4 |
| 47.4 | 4.25 |
| 48.0 | 4.5 |
| 48.6 | 4.75 |
| 49.3 | 5 |
| 49.9 | 5.25 |
| 50.5 | 5.5 |
| 51.1 | 5.75 |
| 51.7 | 6 |
| 52.4 | 6.25 |
| 53.0 | 6.5 |
| 53.6 | 6.75 |
| 54.2 | 7 |
| 54.8 | 7.25 |
| 55.5 | 7.5 |
| 56.1 | 7.75 |
| 56.7 | 8 |
| 57.3 | 8.25 |
| 57.9 | 8.5 |
| 58.6 | 8.75 |
| 59.2 | 9 |
| 59.8 | 9.25 |
| 60.4 | 9.5 |
| 61.0 | 9.75 |
| 61.7 | 10 |
| 62.3 | 10.25 |
| 62.9 | 10.5 |
| 63.5 | 10.75 |
| 64.1 | 11 |
| 64.8 | 11.25 |
| 65.4 | 11.5 |
| 66.0 | 11.75 |
| 66.6 | 12 |
| 67.2 | 12.25 |
| 67.9 | 12.5 |
| 68.5 | 12.75 |
| 69.1 | 13 |
| 69.7 | 13.25 |
| 70.3 | 13.5 |
| 71.0 | 13.75 |
Pro Tips:
- Measure 3-4 times to ensure accuracy
- If between sizes, go with the larger size
- Consider the width of the ring (wider rings typically need a larger size)
Method 2: The Existing Ring Method
What You’ll Need
- A ring that fits perfectly on the intended finger
- A ruler with millimeter measurements
Step-by-Step Instructions
Select Your Ring
- Choose a ring that fits the intended finger
- Make sure it’s a simple band for most accurate measurements
- Clean the ring to ensure accurate measurements
Measure the Inner Diameter
- Place the ring on a flat surface
- Measure across the inside of the ring (diameter)
- Measure from edge to edge in millimeters
- Take multiple measurements for accuracy
Use the Calculator or Chart
- Enter your measurement in our calculator above
- Or reference the size chart below
Ring Method (Inner Diameter Measurement)
| Measurement (mm) | US Ring Size |
|---|---|
| 14.1 | 3 |
| 14.3 | 3.25 |
| 14.5 | 3.5 |
| 14.7 | 3.75 |
| 14.9 | 4 |
| 15.1 | 4.25 |
| 15.3 | 4.5 |
| 15.5 | 4.75 |
| 15.7 | 5 |
| 15.9 | 5.25 |
| 16.1 | 5.5 |
| 16.3 | 5.75 |
| 16.5 | 6 |
| 16.7 | 6.25 |
| 16.9 | 6.5 |
| 17.1 | 6.75 |
| 17.3 | 7 |
| 17.5 | 7.25 |
| 17.7 | 7.5 |
| 17.9 | 7.75 |
| 18.1 | 8 |
| 18.3 | 8.25 |
| 18.5 | 8.5 |
| 18.7 | 8.75 |
| 18.9 | 9 |
| 19.1 | 9.25 |
| 19.3 | 9.5 |
| 19.5 | 9.75 |
| 19.7 | 10 |
| 19.9 | 10.25 |
| 20.1 | 10.5 |
| 20.3 | 10.75 |
| 20.5 | 11 |
| 20.7 | 11.25 |
| 20.9 | 11.5 |
| 21.1 | 11.75 |
| 21.3 | 12 |
| 21.5 | 12.25 |
| 21.7 | 12.5 |
| 21.9 | 12.75 |
| 22.1 | 13 |
| 22.3 | 13.25 |
| 22.5 | 13.5 |
| 22.7 | 13.75 |
Pro Tips:
- Avoid measuring decorative or wide bands
- Ensure the ring is perfectly circular (not misshapen)
- Clean the ring before measuring to avoid debris affecting the measurement
Factors That Affect Ring Size
Several factors can influence your ring size and should be considered when measuring:
Time of Day
- Fingers tend to be larger in the evening
- Measure at the end of the day for best results
Temperature
- Cold temperatures can decrease finger size
- Hot temperatures can cause swelling
- Measure at room temperature
Activity Level
- Exercise can cause temporary swelling
- Wait at least 30 minutes after exercise to measure
Health Factors
- Salt intake can affect finger size
- Pregnancy can cause swelling
- Some medications may cause fluid retention
Final Thoughts and Recommendations
Finding the perfect ring size is essential for both comfort and security. While our calculator and measurement methods are highly accurate, consider these final tips:
- For important rings (like engagement rings), have a professional jeweler verify your size
- If between sizes, choose the larger size, especially in hot climates
- Consider the ring’s width – wider bands typically require a larger size
- For surprise gifts, try to borrow a ring that fits the intended recipient
- Remember that fingers can change size over time due to various factors
By following this guide and using our calculator, you’ll be well-equipped to find your perfect ring size.
Remember that professional jewelers can always adjust your ring size if needed, but starting with an accurate measurement will save time and potential resizing costs.
Remember, the perfect ring isn’t just about style – it’s about fit too. A well-fitted ring should slide over your knuckle with slight resistance and feel snug but comfortable at the base of your finger.
Want to double-check your measurements? Try both methods and compare the results. If they match, you can be confident in your ring size. If they differ, consider visiting a jeweler for a professional measurement.