Spada Jewellers — Melbourne

Ring Sizing Guide

How to measure at home, Australian size charts and international conversions. Get it right before you buy.

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How to Measure
Size Charts

Ring Sizing

Getting your ring size right matters — especially for engagement rings and pieces you plan to wear every day. Most rings can be resized, but it's far easier to order correctly the first time. Use the guides below to measure accurately at home.

Two Ways to Measure at Home

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Paper Strip / String

Wrap a strip of paper around your finger, mark the overlap, measure the length. Works for any finger with no existing ring needed.

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Existing Ring

Already have a ring that fits? Measure its inner diameter with a ruler — the fastest and most accurate method.

Australian Ring Sizes — Common Ranges

Women — Typical Range

Sizes H to Q (Australian/UK)
Most common: J, K, L, M, N
Average: approximately L–M

Men — Typical Range

Sizes Q to Z (Australian/UK)
Most common: R, S, T, U
Average: approximately T

Engagement Rings

If buying as a surprise, ask a trusted friend or family member, or borrow a ring she already wears on her left ring finger. Most common: L (AU).

Resizing

Most gold and platinum rings can be resized up or down by 1–2 sizes. Eternity bands (full circle settings) are harder to resize — size accurately first.

Not sure? Include your measurements when you submit a stone sourcing enquiry and we'll confirm sizing before your ring is set. Better to ask than to resize.

From Spada Jewellers, Melbourne

We source and deliver within 7 business days. If you need to confirm your ring size before we set your stone, just let us know in your enquiry — we can hold the stone and advise before the setting is made.

Paper Strip Method

The most accessible at-home method. All you need is a thin strip of paper, a pen and a ruler. Takes about two minutes and works for any finger.

What You Need

A strip of paper approximately 5mm wide and 10cm long (cut from a sheet of A4)
A pen or fine-point marker
A ruler with millimetre markings

Step by Step

Wrap the paper around your finger

Wrap the strip around the base of the finger you intend to wear the ring on. For most people this is the left ring finger. The paper should sit snugly — not tight, not loose. Make sure it can slide over your knuckle.

Mark the overlap point

Where the end of the paper overlaps the strip, make a clear mark with your pen. This marks the full circumference of your finger at that point.

Measure the length in millimetres

Remove the paper and lay it flat on a ruler. Measure from the end of the strip to your pen mark in millimetres. This number is your inner circumference in mm.

Find your size in the chart

Take your circumference measurement and look it up in the Australian Size Chart panel. If your measurement falls between two sizes, always go up to the larger size.

Measure 2–3 times for accuracy

Repeat the measurement two or three times and average the results. Fingers change slightly throughout the day — measure at different times if you can. See the Tips & Fit panel for the best time to measure.

String alternative: No paper? Use a piece of string or thin ribbon. Wrap it around your finger, mark the overlap with a pen, then lay it flat against a ruler and measure in millimetres. The circumference method is identical.

Tip

Avoid measuring first thing in the morning (fingers are at their smallest) or when you've just come in from the cold. Mid-afternoon, when your hands are warm and at a normal activity level, gives the most representative result.

Existing Ring Method

If you already own a ring that fits the correct finger perfectly, measuring its inner diameter is the fastest and most accurate way to find your size.

Place the ring face-down on a ruler and measure the inside edge to inside edge — this is the inner diameter. Do not measure the outside of the band. Record the measurement in millimetres (mm).

Step by Step

Choose the right ring

Use a ring that fits the same finger on the same hand as the new ring will be worn. The left and right hands can differ in size — use the correct side.

Place it on a ruler

Set the ring flat on a ruler, lining up one inner edge with a millimetre marking. Read off the measurement to the opposite inner edge. This is your inner diameter.

Look up your diameter in the chart

Find your diameter (mm) in the Australian Size Chart panel. The chart lists inner diameter for every AU/UK size letter. If between sizes, go to the next size up.

Account for band width

If the new ring will have a wide band (5mm or more), order half a size to one full size larger than your measurement. Wide bands sit differently on the finger and feel tighter than narrow rings at the same diameter.

Inside Diameter vs Outside

Always measure the inside. The outside diameter includes the band width and varies between ring styles — it's not your ring size.

No Ruler?

Use a coin app or printable ruler. Alternatively, trace the inside of the ring onto paper and measure the circle's diameter with any ruler.

Buying as a Surprise?

Borrow a ring from her jewellery box that she wears on her left ring finger. If you can't borrow it, trace the inside circle onto paper and bring it to a jeweller or include it with your Spada sourcing enquiry — we can size it from the trace.

Australian Size Chart

Australia and New Zealand use the British alphabetical ring sizing system (A through Z+). Find your inner circumference or diameter below to confirm your size.

Highlighted rows are the most commonly ordered sizes

AU / NZ / UK	Diameter (mm)	Circumference (mm)	US / Canada
D	13.1	41.1	1¾
E	13.5	42.5	2¼
F	13.9	43.7	2½
G	14.3	44.8	2¾
H	14.6	46.0	3¼
I	14.9	46.8	3½
J	15.3	48.0	4
K	15.6	49.0	4½
L	15.9	50.0	5
M	16.3	51.2	5½
N	16.6	52.2	6
O	17.0	53.4	6½
P	17.3	54.4	7
Q	17.7	55.6	7½
R	18.0	56.6	8
S	18.3	57.5	8½
T	18.6	58.5	9
U	19.0	59.7	9½
V	19.3	60.6	10
W	19.7	61.8	10½
X	20.0	62.8	11
Y	20.3	63.9	11½
Z	20.6	64.9	12
Z+1	20.9	65.9	12½
Z+2	21.3	66.9	13

Diameter and circumference values are rounded to one decimal place. Small variations (±0.1mm) are normal between manufacturers.
If your measurement falls exactly between two sizes, select the larger size — a ring that's slightly loose is easier to adjust than one that won't go on.
Australian and New Zealand sizing is identical to British (UK) sizing — the same alphabetical system.

Quick Reference

Average Australian women's ring size: L–M (15.9–16.3mm, ~US 5–5.5). Average men's: T–U (18.6–19.0mm, ~US 9–9.5). These are averages only — always measure before ordering.

International Conversion

Ring sizing systems differ by country. Use this table to convert between Australian/UK, US/Canada, European (ISO), Japanese and Swiss sizing. All values cross-reference inner diameter in millimetres.

Full Conversion Table

AU / NZ / UK	US / Canada	Europe (ISO)	Japan	Switzerland	Diameter (mm)
F	2½	43	3	3	13.9
G	2¾	45	4	4	14.3
H	3¼	46	6	5	14.6
I	3½	47	7	6	14.9
J	4	48	8	7	15.3
K	4½	49	9	8	15.6
L	5	50	10	9	15.9
M	5½	51	11	10	16.3
N	6	52	12	11	16.6
O	6½	54	13	13	17.0
P	7	55	14	14	17.3
Q	7½	56	15	15	17.7
R	8	57	16	16	18.0
S	8½	58	17	17	18.3
T	9	59	18	18	18.6
U	9½	60	19	19	19.0
V	10	62	20	21	19.3
W	10½	63	21	22	19.7
X	11	65	22	24	20.0
Y	11½	66	23	25	20.3
Z	12	67	24	26	20.6
Z+1	12½	68	25	27	20.9
Z+2	13	69	26	28	21.3

System Notes

AU / NZ / UK

Alphabetical (D through Z+). Australia, New Zealand, Ireland and the United Kingdom all use this identical system.

US / Canada

Numeric, typically 1–13 with half sizes. No standard for quarter sizes — conversion to AU is always approximate at the half-size boundaries.

European (ISO 8653)

Based on the inner circumference in millimetres. Used across continental Europe (France, Germany, Spain, Italy, Netherlands). The most mathematically precise system.

Japan / China / South Korea

Numeric (1–30+), roughly following inner circumference but offset. Japan size 1 ≈ 13mm diameter. Common in Asian jewellery markets.

Trade Note

If a customer provides a US or European size, always convert via inner diameter in mm rather than direct letter/number mapping — the conversion tables used by different retailers vary slightly. Diameter is the single consistent reference point across all systems.

Tips & Fit

Ring size isn't fixed — it changes throughout the day, with temperature, and between seasons. These guidelines help you measure at the right time and choose the right size for how you actually wear the ring.

When to Measure

Best Time

End of the day, when your hands are warm and slightly swollen from normal activity. This gives your largest natural size — rings should fit at their tightest.

Avoid

First thing in the morning (fingers are at their smallest), after exercise, immediately after eating salty food, or when your hands are cold.

Temperature

Fingers shrink in cold weather and expand in heat. If you wear your ring year-round, measure in normal room-temperature conditions.

Measure Multiple Times

Measure 2–3 times across different times of day and average the results. A single measurement can be off by half a size.

Wide Bands

Wide bands need a larger size. A ring with a 5mm or wider band sits higher on the finger and grips more surface area — it will feel tighter than a narrow ring at the same diameter. As a general rule:

4–6mm band → order ½ size up
7mm+ band → order 1 full size up

If in doubt, round up. A ring that's slightly loose can be resized; one that won't go over the knuckle cannot be worn.

Knuckle Considerations

If your knuckle is noticeably larger than the base of your finger, you'll need to size to fit over the knuckle — the ring will be slightly loose at the base.
A jeweller can fit a sizing bar or sizing beads to the inside of the band to compensate, preventing the ring from spinning.
For significant knuckle-to-base differences (2+ sizes), consider a hinged shank ring designed for this purpose.

Between Sizes

Always go to the larger size when between two sizes — it's easier for a jeweller to size down than to size up without affecting the design.
A ring that's half a size too large can be worn with a temporary ring guard while you arrange resizing.
A ring that's half a size too small will not go over the knuckle and cannot be worn until resized.

Resizing

What Can Be Resized

Most plain gold and platinum bands can be resized up or down 1–2 sizes without visible impact on the ring.

What's Difficult to Resize

Eternity rings (stones set all the way around), rings with patterns that run the full circumference, and some tension-set rings are very difficult or impossible to resize without remaking.

Sizing Up

A jeweller adds a small piece of metal to the shank. Seamless when done well — the ring should look identical afterward.

Sizing Down

A small section of the shank is removed and the ends rejoined. Generally cleaner than sizing up. Easier for most ring styles.

From Spada Jewellers

If you're sourcing a stone from us and aren't certain of the ring size yet, let us know. We can hold the stone and deliver it unmounted, or work with your jeweller directly on the setting once the size is confirmed. No need to rush — get it right.

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