A complete Guinea-Bissau ring-size guide for 2026 โ measure a finger or an existing ring, calculate the nearest metric/EU circumference size, compare Portuguese aro, UK and US equivalents, and use a printable millimetre gauge before buying in Bissau or ordering internationally.
The highlighted ranges are orientation examples rather than gender rules. Finger shape, knuckle width, band profile and the sellerโs own manufacturing tolerances are more important than averages.
A bare label such as โ14โ, โNโ or โ7โ can describe completely different systems. A measurement such as 17.2 mm inner diameter or 54.0 mm circumference can be checked against Portuguese, European, British and American charts without guessing which scale the seller intended.
| ๐ฌ๐ผ Metric / EU Size | โญ Circumference (mm) | ๐ Inner Diameter (mm) | โญ Circumference (cm) | ๐บ๐ธ US Approx. | ๐ฌ๐ง UK Approx. | ๐ต๐น PT / IT / ES Approx. | ๐ค Reference |
|---|
The metric/EU number is based on inner circumference in millimetres. Portuguese aro, UK and US equivalents are rounded comparisons; manufacturers may group or round sizes differently.
Use the hand on which the ring will be worn. Finger dimensions can differ between the left and right hand, and the dominant hand can be slightly fuller. Remove other jewellery and let the hand rest before starting.
Use ordinary paper about 5โ8 mm wide or a flexible measuring tape that does not stretch. Elastic thread, soft string and thick cord can compress the skin or change length, producing a misleading result.
Place the strip where the ring will sit. It should touch the skin without squeezing it, while the loop must still pass over the knuckle with gentle resistance. Measure both the finger base and knuckle when their widths differ noticeably.
Mark the exact overlap with a fine pen, open the strip and measure the length from the starting edge to the mark. A 54 mm circumference is near metric/EU size 54 and often close to Portuguese aro 14. Enter 54 mmโnot 5.4 mmโinto the calculator.
Take at least three readings at different times under normal conditions. Avoid measuring immediately after strenuous activity, prolonged heat, carrying heavy items, a very salty meal or extended exposure to strong air conditioning.
Use a round ring that fits the intended finger comfortably. A ring from another finger is not a reliable substitute.
Place the ring flat and measure the widest internal opening straight through the centre. Exclude both metal edges.
Rotate the ring by about 90 degrees and repeat. Different results can indicate an oval or distorted ring.
17.2 ร ฯ โ 54.0 mm circumference โ metric/EU size 54 for comparison with a Guinea-Bissau seller.
A digital calliper is usually more repeatable than reading a thick ruler. When using a ruler, align one internal edge with zero and view from directly above to reduce parallax error.
First measure the calibration line. It must be exactly 50 mm. Place a comfortable ring over the circles and match the inside edge of the metal to the outside edge of the printed circle. Do not use โFit to Pageโ, โShrinkโ or automatic scaling.
Example: 54.0 mm circumference is approximately size 54.
Example: 17.19 mm ร 3.1416 โ 54.0 mm.
Example: 54.0 mm รท 3.1416 โ 17.19 mm.
Example: EU 54 is approximately Portuguese/Italian/Spanish size 14.
US sizes use a separate scale and quarter sizes, so the result is approximate.
UK sizes use letters and half letters. Keep the millimetre reading for accuracy.
Warm conditions can make a normally comfortable ring feel tighter later in the day.
Exercise, walking and fluid retention can change the result for a short time.
A broad wedding band covers more skin and can need additional space.
The ring must pass the knuckle while remaining reasonably secure at the base.
Dominant and non-dominant hands do not always have identical finger sizes.
Rounded interiors can feel different from flat interiors at the same diameter.
Thin fashion rings and many engagement-ring shanks usually create less pressure. A carefully repeated home measurement may be close to the final size, but top-heavy settings can still spin even when the circumference is correct.
A broad band covers more skin and resists movement. The same internal opening may feel tighter than a narrow ring. Do not add a fixed size automatically; test a sample of similar width or follow the maker's recommendation.
Ask about resizing and returns before paying, especially when the ring is imported or made to order. Plain gold or platinum bands are often easier to adjust than full-eternity rings, tension settings, ceramic rings, patterned bands, heavily plated jewellery or rings with stones around most of the circumference.
These established references support the measurement method and international comparisons used in this guide. The sellerโs product-specific table should still be used for the final order.
The international standard page covering ring-size measurement and designation.
Explains how to measure an existing ringโs inside diameter and compare Portuguese sizing with international systems.
A Portuguese jewellery reference for determining a ring size and reviewing measurement guidance.
A consumer guide for comparing circumference and diameter measurements with a retailerโs size chart.