Chapter 03 · The Fit

Find your fit.

Choosing a swim brief shouldn't feel like a guess. This guide walks you through it the same way our team would. One reference point, three measurements, and a short read on each of our cuts.

Use a swim brief you already own as your reference. If you are between sizes or prefer less compression, size up. Our lycra-blend fabrics relax slightly with the first wears. That is normal.

The method

Three steps to your size.

The fastest path is a brief you already wear. The whole thing takes a minute.

  1. Start from a brief you own

    The fastest path to the right size is a swim brief that already fits well. Use it as your reference. If you don't have one, measure your waist where you'd wear a swim brief, not at the trouser line.

  2. Lay flat, measure, multiply by two

    Place the brief on a flat surface without stretching the waistband. Measure edge to edge across the front, then multiply by two for the full circumference. Compare that number to the garment table below.

  3. Decide on fit

    Between sizes? Size down for a firm, sculpted fit; size up for daily comfort. If you have a narrower waist and broader hips, size up. That combination usually benefits from the extra mobility.

Body conversion

Waist conversion.

Use your waist circumference, not your trouser size. Measure at the natural waistline. The BR column is the Brazilian sizing standard. The EU column is the European jersey equivalent.

Size Waist (in) Waist (cm) BR EU
XS 26 – 28 66 – 71 PP 44
S 28 – 30 71 – 76 P 46
M 30 – 32 76 – 81 M 48
L 32 – 34 81 – 86 G 50
XL 34 – 36 86 – 91 GG 52
XXL 38 – 40 96 – 101 XGG 54

If your waist falls between sizes, choose the smaller for a firm fit, the larger for daily comfort.

Garment measure

The brief itself.

The most reliable check. Lay a brief you own flat without stretching, measure the waistband edge to edge, multiply by two. Compare that number to the table below.

Size Garment waist (in) Garment waist (cm)
XS ≈ 28.7 – 29.1 ≈ 73 – 74
S ≈ 29.5 – 29.9 ≈ 75 – 76
M ≈ 31.5 – 31.9 ≈ 80 – 81
L ≈ 33.1 – 33.5 ≈ 84 – 85
XL ≈ 37.0 – 37.4 ≈ 94 – 95
XXL ≈ 37.8 – 38.2 ≈ 96 – 97

Garment measured flat, without stretching. Lycra-blend fabrics relax slightly with use. This is intentional.

Cut by cut

How each cut sits.

Five cuts, five silhouettes. The number that matters most is side width: the panel that determines how much skin reads on the body. Listed narrowest to widest.

  • Nanica Slim

    Side width
    3 cm · 1.2 in
    Coverage
    Low

    Our most daring silhouette. A graphic, narrow side that draws a sharp line on the body. Close-cut, deliberate, and unafraid.

    Shop Nanica Slim

  • Nanica

    Side width
    6 cm · 2.4 in
    Coverage
    Standard

    Our signature cut. Anatomical and contemporary, with a side that follows the body without overstating it.

    Shop Nanica

  • Ouro

    Side width
    9 cm · 3.5 in
    Coverage
    Medium

    Our medium-width classic. Named after gold. Structured side panels and an anatomical front. The cut that introduced many to the brand.

    Shop Ouro

  • Terra

    Side width
    12 cm · 4.7 in
    Coverage
    Full

    A grounded cut with fuller coverage and a confident proportion. Built to be lived in.

    Shop Terra

  • Terra Wide

    Side width
    17 cm · 6.7 in
    Coverage
    Wide

    Our widest cut. Architectural sides, generous coverage. A confident silhouette for those who want their swimwear to read as a statement.

    Shop Terra Wide

Two things worth knowing

Small details, real difference.

  • Body type

    Narrower waist, broader hips? Size up.

    If your waist is on the smaller side and your hips or glutes are fuller, a size up tends to read better. Extra ease through the leg, more freedom of movement. The waistband still holds; the silhouette doesn't pinch.

  • Fabric behavior

    Lycra relaxes slightly with wear.

    Our blends are built to recover. The first wears will feel firm; after a few hours the fabric finds its memory. This is intentional. If you're choosing between sizes for the first time, that small relaxation is the reason we suggest sizing for the firm fit unless you want pure ease.

Still unsure

Talk to a human.

If you've measured and the answer still isn't obvious, our team in São Paulo is the fastest way through. We help before, during, and after every order. Fit, fabric, shipping, returns.

BANNANNA Service · São Paulo