The most reliable way to find your ring size at home is to measure the inside diameter of a ring that already fits that finger and match it to a size chart. If you don't have one, wrap a strip of paper around the base of the finger, mark where it overlaps, and measure the length: 54.4 mm around is a US size 7. Measure at the end of the day, and size up a half size for bands wider than 6 mm.
Ring sizing is the step most people rush, and it causes most returns. The good news is that you can measure accurately at home in five minutes with things you already own. Here is how, plus the chart to convert your measurement into a US ring size.
Method 1: Measure a ring that already fits
This is the most accurate home method, because a ring has a fixed inside diameter.
- Pick a ring that fits the same finger on the same hand. Fingers on your dominant hand are often slightly larger.
- Lay it flat on a ruler and measure the inside diameter in millimeters, edge to edge across the widest point. Don’t include the metal.
- Match the number to the chart below.
If your measurement falls between two sizes, choose the larger one.
Method 2: The paper strip method
No ring to measure? Use a strip of paper about 5 mm wide (string works too, but it stretches).
- Wrap the strip around the base of the finger, snug but not tight.
- Mark where the paper overlaps with a fine pen.
- Unwrap it and measure from the end to the mark in millimeters. This is your circumference.
- Check that the strip will slide over your knuckle. If your knuckle is larger than the base of your finger, measure the knuckle too and use a size between the two.
US ring size chart
| US size | Inside diameter | Circumference |
|---|---|---|
| 4 | 14.9 mm | 46.8 mm |
| 5 | 15.7 mm | 49.3 mm |
| 6 | 16.5 mm | 51.9 mm |
| 7 | 17.3 mm | 54.4 mm |
| 8 | 18.2 mm | 57.0 mm |
| 9 | 19.0 mm | 59.5 mm |
| 10 | 19.8 mm | 62.1 mm |
| 11 | 20.6 mm | 64.6 mm |
| 12 | 21.4 mm | 67.2 mm |
| 13 | 22.2 mm | 69.7 mm |
Each half size adds roughly 0.4 mm to the diameter and 1.3 mm to the circumference. UK sizes use letters (a US 7 is about a UK N or N½), so check the jeweler’s own chart if you order from abroad.
When to measure
Fingers change size through the day. Heat, salt, exercise and travel make them swell, and cold makes them shrink. For the most accurate result:
- Measure in the evening, at room temperature.
- Measure two or three times on different days if you can.
- Avoid measuring right after a workout, a hot shower or a salty meal.
Adjusting for the band
The size on the chart assumes a standard band of about 2 to 4 mm. Adjust for:
- Wide bands (6 mm and up): go up a quarter to a half size.
- Comfort-fit bands (rounded on the inside): these feel looser, so you may stay at your measured size even with a wide band.
- Stacking rings: each ring is sized on its own, but a stack of several thin bands feels like one wide band.
Sizing a ring as a surprise
If the ring is a gift, borrow one your partner wears on the same finger and measure it as in method 1, or press it into a bar of soap to keep an impression. Ask a friend or family member who might know. When in doubt, size slightly up: making a ring smaller is usually easier and cheaper than making it larger, and many jewelers offer one free resize.
Rings you can’t easily resize
Before you buy, check whether the ring can be resized:
- Eternity bands with stones all the way around can’t be resized without resetting stones.
- Tungsten, titanium and ceramic rings generally can’t be resized at all.
- Rose and white gold can be resized, but white gold usually needs re-plating with rhodium afterward.
For these, a jeweler’s ring sizer or a free sizing kit from the retailer is worth the wait.
Common questions
What is the most common ring size?
For women in the US, sizes 6 to 7 are the most common, and for men, sizes 9 to 10. That is a starting point, not a substitute for measuring, because the right size depends on your knuckle and the width of the band.
Should a ring be tight or loose?
A ring should slide over your knuckle with a little resistance and sit snugly at the base of the finger without spinning freely. If it leaves a deep mark or you can't get it off with soap, it is too small.
Do wide bands need a bigger size?
Usually yes. Bands wider than about 6 mm cover more of the finger and feel tighter, so most jewelers recommend going up a quarter to a half size.
Can a ring be resized later?
Most gold, silver and platinum rings can be resized by one or two sizes. Eternity bands, rings with stones all the way around, and tungsten or titanium rings usually can't, so get the size right before you order those.