Forge Custom Ring
Not sure of your size?
Pick the closest. Every order comes with one free 30-day size exchange. We cover the shipping both ways. So you can commit without locking in a number.
The fastest way: measure a ring you already own
Grab a ring that fits the finger you're sizing for. With a millimeter ruler, measure the inner diameter, straight across the inside of the band. Match the millimeters to the Inner Diameter (mm) column below.
This is the most accurate method and takes 30 seconds. No supplies beyond a ruler.
Method 2: Measure your finger with string
Wrap a length of string or ribbon around your finger. Make sure it crosses over the knuckle so the ring will slide on and off easily.
Mark where the string meets, lay it flat, and measure the length in millimeters. Match the millimeters to the Circumference (mm) column below.
Method 3: Print our ring sizer
Download the printable ring sizer →
Print it actual-size (100% scale, no "fit to page"), cut out the sizer strip, and wrap it around your finger. Follow the instructions on the sheet.
Size conversion chart
| US Size | Inner Diameter (mm) | Circumference (mm) |
|---|---|---|
| 5 | 15.7 | 49.3 |
| 5.5 | 16.1 | 50.6 |
| 6 | 16.5 | 51.9 |
| 6.5 | 16.9 | 53.1 |
| 7 | 17.3 | 54.4 |
| 7.5 | 17.7 | 55.7 |
| 8 | 18.2 | 57.0 |
| 8.5 | 18.5 | 58.3 |
| 9 | 19.0 | 59.5 |
| 9.5 | 19.4 | 60.8 |
| 10 | 19.8 | 62.1 |
| 10.5 | 20.2 | 63.4 |
| 11 | 20.6 | 64.6 |
| 11.5 | 21.0 | 65.9 |
| 12 | 21.4 | 67.2 |
| 12.5 | 21.8 | 68.5 |
| 13 | 22.2 | 69.7 |
| 13.5 | 22.6 | 71.0 |
| 14 | 23.0 | 72.3 |
| 14.5 | 23.4 | 73.6 |
| 15 | 23.8 | 74.8 |
| 15.5 | 24.2 | 76.1 |
| 16 | 24.6 | 77.4 |
A few measuring tips
- Fingers swell in warmth and shrink in cold. Measure at the end of the day, when warm for the most accurate result.
- The string or sizer should fit snugly but not tight. A well-fitting ring slides over the knuckle with light pressure.
- Avoid measuring when your hands are cold or wet.
- Between sizes? Go up. A slightly loose ring is wearable, and a tight ring isn't. And the free exchange has you covered either way.
Still unsure?
Email help@foundrycut.com with your situation. We reply within one business day and can usually pin down the right size from a couple of questions.
Built in The Forge. A one-of-a-kind ring configured by you, forged to order. You choose the material, accent, inlay, interior, width, and size. Your exact build specifications are attached to this order.
- Material: per your build
- Widths: 6 mm / 8 mm
- Sizes: 5-16 (half sizes available)
- Made to order
Use our free printable ring sizer or measure a ring you already wear on the same finger. If the size is wrong, free 30-day size exchanges have you covered.
Free shipping on US orders. Some rings ship within 1 business day. Made-to-order pieces ship in 2 to 4 weeks (we'll confirm timing at order).
Every ring is covered by a lifetime limited warranty against manufacturing defects. Email help@foundrycut.com with your order number to file a claim.
