The quickest way to find your ring size at home is to measure the circumference of your finger with a strip of paper and subtract 40 from the result in millimeters. If the circumference is 52 mm, your Spanish size is 12. That’s the short method; below you’ll find the four that really work and the complete conversion chart.
What Ring Size Means
In Spain, a ring size is the inner circumference of the piece in millimeters minus 40. A size 14 ring has a 54 mm inner circumference. It’s a different convention from the American system (which runs from numbers 3 to 13) and the British system (which uses letters), so it’s important to know which system you’re measuring in before ordering anything.
The average size in Spain is between 12 and 14 for women’s fingers and between 18 and 22 for men’s fingers, but it’s just a reference: variation between people is huge and between fingers on the same hand as well.
Method 1: The Paper Strip (Most Reliable Without Tools)
- Cut a strip of paper one centimeter wide and about ten long. Don’t use stiff paper or adhesive tape.
- Wrap it around the base of the finger where you’ll wear the ring, fitting snugly without squeezing.
- Mark with a pen the exact point where the strip overlaps.
- Straighten it out and measure from the end to the mark with a ruler, in millimeters.
- Subtract 40 from that number. The result is your Spanish size.
Example: 55 mm circumference minus 40 equals size 15.
Always check that the strip passes over the knuckle. If the knuckle is wider than the base of the finger, measure the knuckle: that’s the point the ring has to pass through.
Method 2: Using a Ring You Already Own
If you already have a ring that fits well on that finger, this is the easiest method:
- Measure the inner diameter of the ring with a ruler, from inside edge to inside edge.
- Multiply that diameter by 3.1416.
- Subtract 40 from the result.
Example: a ring with a 17 mm inner diameter has a 53.4 mm circumference, so the size is 13.
Method 3: The Ring Sizer
This is the set of numbered rings that jewelry stores use. You try on rings until you find the one that goes on snugly but comes off without forcing, and that number is your size. It’s the most accurate method of all and the one we use when someone stops by the shop.
Inexpensive plastic ring sizers are available. If you’re going to buy several rings over time, it’s worth it.
Method 4: Mobile Apps
There are apps that calculate size by placing a ring you already own on the screen. They work reasonably well as a check, but they depend on the screen being properly calibrated, so we wouldn’t use them as the only measurement for a ring that can’t be resized.
Ring Size Conversion Chart
| Inner Circumference (mm) | Inner Diameter (mm) | Spanish Size |
|---|---|---|
| 46 | 14.6 | 6 |
| 48 | 15.3 | 8 |
| 50 | 15.9 | 10 |
| 52 | 16.6 | 12 |
| 54 | 17.2 | 14 |
| 56 | 17.8 | 16 |
| 58 | 18.5 | 18 |
| 60 | 19.1 | 20 |
| 62 | 19.7 | 22 |
| 64 | 20.4 | 24 |
| 66 | 21.0 | 26 |
If your measurement falls between two sizes, go up to the larger one. A slightly loose ring can be worn; one that won’t pass the knuckle can’t.
Five Mistakes That Ruin the Measurement
- Measuring when cold. Fingers contract. Measure with your hands at normal temperature, never right after coming in from outside in winter.
- Measuring late in the day. Fingers swell in the afternoon and after exercising or eating salty food. The best time is mid-morning.
- Forgetting the knuckle. It’s the critical point: if the ring won’t pass through there, the size at the base doesn’t matter.
- Using string or thread. It stretches and distorts the result. Always use paper.
- Measuring one finger for another. Each finger has its own size, and the dominant hand is usually between half a size and a full size larger.
How to Get It Right If It’s a Gift
Without the other person knowing, you have three options: borrow one of their rings and measure the inner diameter, ask someone they trust who already knows, or go with the average size (12-14 for women’s fingers, 18-22 for men’s fingers) knowing you may need to adjust it later.
If you want to play it safe, a personalized bracelet or pendant allows much more room for error than a ring.
You Have Your Size
With the measurement in hand, the next step is choosing the piece. Our personalized rings are designed and made in Málaga, and you can personalize your accessory with the symbol, initial, or date you want it to carry.
Frequently Asked Questions
How Do I Find My Ring Size Without a Sizer?
Wrap the base of your finger with a strip of paper, mark where it overlaps, measure that length in millimeters, and subtract 40. That number is your Spanish size.
What Ring Size Is 17 mm?
If we’re talking about inner diameter, 17 mm equals about 53.4 mm circumference, which is a Spanish size 13.
What Ring Size Equals 6 cm?
A circumference of 60 mm corresponds to Spanish size 20.
What Time of Day Should I Measure My Finger?
Mid-morning, with your hands at normal temperature. In the afternoon and when warm, fingers swell and the measurement comes out larger than it really is.
What Do I Do If I’m Between Two Sizes?
Choose the larger one. A slightly loose ring is preferable to one that won’t pass the knuckle.
Is the Size the Same on Both Hands?
Not necessarily. The dominant hand usually needs between half a size and a full size more.
