A Simple Guide from Black Diamonds – New York
At Black Diamonds – New York, we want every piece you order to fit beautifully and comfortably. One of the most common issues when buying rings online is sizing, which is why we recommend taking a few minutes to measure your finger before placing your order.
The good news is, you don’t need special tools or a trip to the jeweler. You can easily measure your ring size at home using simple DIY methods.
Easy Ways to Measure Your Ring Size at Home
1. String or Paper Method (Quick & Reliable)
This is one of the easiest and most popular ways to measure your ring size.
What you’ll need:
A thin strip of paper or string
A pen or marker
A ruler (millimeters preferred)
Steps:
Wrap the string or paper snugly around the base of your finger.
Make sure it’s comfortable, not too tight.
Mark where the ends meet.
Lay it flat and measure the length in millimeters.
Match the measurement to a ring size chart.
💡 Tip: Measure at the end of the day when your fingers are at their largest.
2. Measure a Ring You Already Own
If you already have a ring that fits well, this is one of the most accurate methods.
Steps:
Place the ring on a ruler.
Measure the inside diameter of the ring (edge to edge).
Match the diameter to a standard ring size chart.
Important Ring Sizing Tips
Avoid measuring when your hands are very cold or swollen.
Wider bands often feel tighter; you may want to size up slightly.
If you’re between sizes, we usually recommend sizing up for comfort.
Dominant hands can be slightly larger; measure the finger you plan to wear the ring on.
Need Help Before You Order?
If you’re unsure about your size or between sizes, our team at Black Diamonds – New York is always happy to help before you place your order. Taking a moment to confirm your size helps ensure the best experience and a ring you’ll love wearing every day.
Standard US ring sizes generally follow a consistent conversion for inside diameter (the distance across the center of the ring's interior). Here is a confirmation of your measurements alongside the inside circumference, which is often easier to measure at home using a string or paper strip:
| US Ring Size | Inside Diameter (mm) | Inside Circumference (mm) |
| Size 5 | 15.7 mm | 49.3 mm |
| Size 6 | 16.5 mm | 51.9 mm |
| Size 7 | 17.3 mm | 54.4 mm |
| Size 8 | 18.1 mm | 57.0 mm |
| Size 9 | 18.9 mm | 59.5 mm |
| Size 10 | 19.8 mm | 62.1 mm |
| Size 11 | 20.6 mm | 64.6 mm |
| Size 12 | 21.4 mm | 67.2 mm |
