Method 1 — Measure a ring that already fits
This is the best at-home method when the ring fits the same finger you are sizing.
- Place the ring flat on a ruler or the calibrated on-screen ring sizer.
- Measure straight across the widest part of the inside opening.
- Do not include the metal band in the measurement.
- Match the inside diameter in millimetres to the ring size chart.
Method 2 — Paper strip around your finger
No ring to copy? A strip of paper gives you the finger's circumference.
- Cut a strip of paper about 5 mm wide and 10 cm long.
- Wrap it comfortably around the base of your finger. Check that the marked loop can also pass over your knuckle.
- Mark with a pen exactly where the end meets the rest of the strip.
- Lay the strip flat on a calibrated on-screen ruler and read the mark.
A ruler displayed on a screen must be calibrated because display scale varies by device. RingSize.app calibrates the ruler to a credit card or coin before you measure.
Method 3 — String and ruler
Use the same steps with thin, non-stretchy string. Do not pull it tight: stretching or compressing the finger changes the result. Paper is usually easier to mark consistently.
Method 4 — Use a printable chart carefully
Printable ring size charts are everywhere online. The problem: printers silently re-scale. Even with "Actual size" / 100% scaling, results vary by printer. If you must, print at 100%, then verify with a ruler that the test square on the chart is exactly 1 inch wide before trusting any of the sizes.
Common ring size measurements
These popular whole sizes are useful reference points. Use the full chart for quarter and half sizes.
| US size | Inside diameter | Inside circumference |
|---|---|---|
| 5 | 15.7 mm | 49.3 mm |
| 6 | 16.5 mm | 51.9 mm |
| 7 | 17.3 mm | 54.4 mm |
| 8 | 18.1 mm | 57.0 mm |
| 9 | 18.9 mm | 59.5 mm |
| 10 | 19.8 mm | 62.1 mm |
Want a physical backup?
Confirm the result by hand before an expensive or non-resizable purchase, then shop with confidence.
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Pro tips for accurate sizing
- Avoid measuring when very cold or hot. Wait until your hands are at a normal, comfortable temperature.
- Measure 2 – 3 times. Compare readings at different times; single measurements are easy to misread.
- Account for knuckle. If your knuckle is significantly larger than your finger base, size up so the ring slides on comfortably.
Frequently asked questions
How can I measure my ring size at home?
Measure the inside diameter of a ring that fits the intended finger. Without a ring, measure the finger circumference with a paper strip and convert the millimetres on the chart.
Can I measure ring size without a ring?
Yes. Wrap a narrow paper strip around the finger, mark the overlap, lay it flat and measure the marked length. Repeat it to check the result.
When is the best time to measure?
Measure when your hands are at a normal, comfortable temperature. Compare more than one reading and make sure the chosen size passes over your knuckle.