How to Measure Ring Size Secretly?
24.02.2026 · updated 28.08.2026 · Rauno Oidram
In Estonia a ring size is the ring's inner diameter in millimetres: size 17 means a 17 mm diameter. The most common women's sizes are 16.5–17.5, men's 19–21. The same measurement carries a different number in the EU table — the circumference, where 17 is EU 53 — but you order from us in millimetres. There are three reliable ways to measure: from an existing ring, with our on-screen sizer right on your phone, or with the thread method. If the result lands between two sizes, choose the larger.
1. Most accurate: an existing ring
If you can borrow a ring she wears on the same finger (this matters — fingers on the same hand differ by up to two sizes), you have two options:
- Lay the ring on our on-screen sizer — calibrate with a bank card and read the size in under a minute.
- Or measure the ring's inner diameter with a ruler — that number is the size. For example 17.2 mm is size 17 (EU 53).
2. Without a ring: the thread method
If there is no ring to borrow, wrap a thread or a narrow paper strip around the finger, mark the overlap, and measure the length in millimetres. That is the circumference, which is the EU size; divide it by 3.14 for the size in millimetres — 53 mm ÷ 3.14 ≈ 17. Measure in the evening — fingers are slimmer in the morning — and never right after sport or in the cold. The most exact answer, though, is two minutes at the atelier with proper sizing rings on the finger itself.
3. Measuring in secret
- Borrow a ring "for cleaning". A friend or family member asks to try it on or takes it "to be cleaned" — two minutes at our atelier is enough for an exact measurement.
- The soap method. Press her ring briefly into a bar of soap or putty and bring us the impression. Less exact, but with our experience usually enough.
Honestly: if the secret measuring fails, it is not a catastrophe. Propose with a size 17 — our first resize is free within the first year and takes a few days.
Between two sizes
Always choose the larger, so the ring actually goes on at the moment that matters. A tight ring cannot be worn — it sticks at the knuckle. A slightly loose ring can be sized down precisely. Wide bands (over 6 mm) sit tighter: go 0.5–1 mm up for those.
Read next: Ring size · When to order an engagement ring? The timeline that saves the proposal · How to Choose an Engagement Ring
Frequently asked
What is the most common women's ring size?
In Estonia the most common women's engagement ring sizes are 16.5–17.5 mm (EU 52–55), most often 17. Men's wedding bands mostly fall between 19 and 21 mm.
Can a ring be resized later?
Yes. Most rings can be sized up or down by 1–2 mm; the first resize at Keefirivunts is free within the first year. Full eternity bands are the exception — talk to us first.
How accurate is measuring on a phone screen?
Calibrated against a bank card, the on-screen sizer is accurate to about half a size — enough to tell 16.5 from 17.5. If the result sits on a boundary, choose the larger size or spend two minutes at the atelier for an exact measurement.
What time of day should a finger be measured?
In the evening, at room temperature. Fingers run up to a size slimmer in the morning and in the cold, and temporarily thicker after sport or salty food.
Rauno Oidram — goldsmith, Keefirivunts
Designs the Keefirivunts rings and personally chooses every stone.
