Sizing Guide

What to look for when buying a bra

Our garments are made to flatter and accentuate the body, but in order for them to look their best, they need to fit correctly.

When fitting a bra we recommend you try it on the loosest fastening (front-fastening bra’s excluded) as once you have worn and washed it a few times it is likely to get looser and less supportive – the horizontal strap or underband of the bra is one of the most important areas of fit as it supports your bust from the chest wall, therefore if it is firm the bra will be more supportive.

Always remember to move around when trying on a bra; this will let you know if it is fitting correctly and that it is supportive enough for you.


  • The Underband should be horizontal across your back. It should be snug but with enough room to fit two fingers underneath.
  • If the underband is riding up or your breasts are showing beneath, then you will need to go down a back size.
  • If the underband is too snug, and physically uncomfortable then going up a back size will help with this. This however should not be mistaken with the bra being firm.


  • The wires at the front should sit flat at the breastbone, and sit around your breast tissue, not on the breast tissue.
  • If the wires are digging into your breast tissue or the wires are lifting away from the breastbone, then increasing the cup size will stop this.
  • If the wires are slipping down your body, towards your waist or are sitting further around your body/underarm than they should, then going down a cup size will help prevent this.


  • Your breast should be fully enclosed in each cup and there should be a smooth line where the cup ends. When fitting a bra, we always fit the cups to the larger breast. The average woman will often have one breast larger then the other; this is not abnormal. However, to get the correct fitting bra, we will always fit to the larger breast to reduce the chance of the breast bulging out of the bra cup.
  • If your breasts are spilling out of the cups at the front or under the arms, increase the cup size.
  • If the bra cups are wrinkling or gaping then going down a cup size will help.


  • The bra straps should be secure, but not tight. You should be able to run a finger underneath the straps without too much difficulty.
  • If the straps are digging into your shoulders or are causing the cups to dig into your breasts, loosen the straps.
  • If you are finding your straps are slipping off your shoulders then tighten the straps. NB. If you have narrow set shoulders, try to avoid balcony style bras as these have wide set straps, and you may find that these will slip off easily.
  • For further reading on bra styles and which ones will suit you best, go to our glossary section.


Lascivious swim is sized in UK dress sizes, from a size 6 through to a size 16. Please refer to the guide below for equivalent sizes. 
Please note this is only a guide, if you have any questions please email the team - 

Bikini Bottoms 

UK SIZE 6 8 10 12 14 16
USA SIZE 2 4 6 8 10 12
EUROPEAN SIZE 34 36 38 40 42 44

Bikini Bra Tops

UK DRESS SIZE 6 8 10 12 14 16

32A, 30B

34A, 32B, 30C

36A, 34B, 32C, 30D

36B, 34C, 32D,30DD

36C, 34D, 32DD, 30E

36D, 34DD, 32E, 30F




UK  8 64 78 89
UK  10 69 83 94
UK  12 74 88 99
UK  14 79 93 104
UK  16 84 98 109


UK SIZE 8-10 10-12 12-14


USA SIZE 4-6 6-8 8-10
EUROPEAN SIZE 36-38 38-40 40-42
RUSSIA SIZE 42-44 44-46 46-48



UK 30 32 34 36
USA 30 32 34 36
EUROPE 65 70 75 80
AUSTRALIA 8 10 12 14
FRANCE 80 85 90 95
JAPAN 50 60 70 80
ITALY 0 1 2 3



To find out what bra size you are, use a tape measure to get two measurements around the bust area, the underband and the overbust.


UnderhandUnderband - The circumference around your body just under the bust, on the ribcage.

OverbustOverbust – The circumference around your body over the fullest part of your bust. When measuring, lay the tape measure over your nipples, this is where the fullest part of your bust is.

Make sure the tape measure is firm when you are taking your underbust measurement, but not so tight that it hurts. When measuring your overbust, the tape measure should be held more loosely around the bust so as not to indent the body.

First, take the tape measure and wrap it around the underbust firmly, unlike most stores, we use the measurement without adding any extra inches on; this will give you a bra that will fit to your measurement, not looser.

The underband measurements come in even numbers: 30, 32, 34, 36 and so on. If your measurement is an odd number, round it up, so as to not have your underband too tight.

For example:

Measured: 33” round up to 34”

Measured: 30.5” try a 30”, if this feels too tight, increase to 32”

To measure your overbust/cup, lay the tape measure lightly over the nipples and around the back; ensuring it is straight all the way around the body (it may be helpful to get someone else to measure you so they can see the tape measure clearly). The measurement will either be bigger, or the same as the underband measurement. You can get the cup size from the difference between the underband and overbust measurement.

If both measurements are the same, the cup size would be an A-cup, if the overburst measurement is 1” larger, this would be a B-cup, if it was 2” larger this would be a C-cup and so on.

For example:

Underband: 34”

Overbust: 38”

Looking at the chart below, and the measurements in the example, this person would be a 34DD bra.

34 35 36 37 38 39 40

If you find the overbust measurement is in between sizes e.g. 36.5” then round it up to 37 for the overbust. It’s better to go for a slightly bigger cup, than smaller to avoid any bulging out.

The method above is standardised to give you an approximate idea of your size. Our signature fit may feel neater than mass produced, high-street brands, but is broadly true to size. We try to be as accurate as possible within the individual product descriptions, but please note that fit will vary between styles depending on the fabric and design, so we recommend contacting us if you are unsure.



Always hand-wash your garments, this reduces the risk of stretching and warping the fabric, which can happen if placed in the washing machine. It will also reduce the risk of the fabric snagging on other clothes.

Wash light and dark colours separately, this will stop any colour transfer.

Use a lingerie specific detergent, or a neutral detergent.

Do not wring, rub or spin dry an lingerie, hang them up to dry or lie flat. This will keep your lingerie from distorting. Reshape padded bras while damp so they dry in the correct shape.

Store your bras upright to avoid crushing them. 

Hand-wash hosiery separately (as bra hooks and fastenings can catch) and allow to drip dry over a bath or shower. We DO NOT replace or refund machine washed products.

Latex must be stored in a cool, dark place and wiped clean with a damp cloth. Do not use oils or lotions on or near your latex, as it may degrade the quality and colour.

We recommend that you dry-clean our corsetry, however we cannot accept any responsibility for damage incurred during this process.



Balcony Bra

A Balcony bra, is one, which simulates a balcony shape, the cut of the cups reveals the upper part of the breast. The straps are at the side of the cups, usually where the wire sits. The cups can be padded, non-padded or partially padded, and can give a variety of support and highlighting to the breast.

These bras are not suitable for wearing under a plunging neckline, as the center front of the bra will show.

Classic Bra

This style of bra, will tend to cover all of the breast, however, we may include cut out detailing to add a little bit of fun to a standard shape. The straps tend to be central to the neckline, at the apex point. The bra will always be underwired, but can be padded or non-padded.

These bras are great to wear everyday under most clothing.

Cupless/Open Cupped Bra

One of the most popular bra styles by Lascivious is a cupless bra. This is where the bra is underwired; however does not have any cup to hold the breast in and there may be a fabric detailing that comes from the neckline for modesty.

These bras are more for bedroom wear than everyday. However, Lascivious do offer some ranges that are cupless and also wearable as an every day option. They only come in a smaller range of sizes, due to the nature of the bra; it can be less flattering on larger sizes.

Triangle Bra

Usually non-wired, the neckline and cups are of a triangular shape and have the straps central, with a low back.

Although thought only flattering on the smaller bust, due to strength in fabric technology, these can now be available to larger sizes and offer the same amount of support.

Bralette Bra

A bralette, tends to be non wired, and will usually have a lining to give extra support to the breast. It is similar to a fitted crop top, however, using a more lingerie based fabric.

Frame Bra

A frame bra is similar to a cupless bra however it is non-wired and simply frames the breast. It is also similar to a triangle bra, as it also has central straps and the neckline and cups are triangular in shape.

Strapless Bra

As the name suggests, a strapless bra has no straps. The bra can have straps attached, and they would be in the same place as a Balcony bra. The cups cover the breast with a high back to give support. It can be padded or non-padded and is often trimmed with silicone to make it easier to wear, preventing it from slipping. Perfect for wearing under strapless dresses, with thin or awkwardly placed straps.

Push-Up Bra

This style of bra is characterised by the slant of the cups and helps to push together the breasts. The padding offers full coverage (moulded), or just the lower half, and forms a rounded shape which greatly increases the proportions.



A knicker with either a front or back opening. It can either have a fastening, or be fully open and designed in either a brief or thong/g-string style. These tend to be more bedroom wear, however, if they have a fastening and are comfortable, they can be worn as an everyday brief.


A standard shaped knicker, these can have a high, medium or low rise in the waist and cut on the leg line, it depends on the hip shape.


A brief with a reduced back, leaving the bottom showing- It is a great brief to wear when there is a chance of a knicker line showing, as the rise of the back sits in between the butt cheeks.

Big Knickers

A brief but with a high waistline. Tends to sit on the waist, rather then the hip and can help give tummy control without compromising on style. These briefs can really define a figure and show off curves.


Very similar to the brief style, but the front and back are reduced and the sides replaced with either a thin piece of fabric or elastic.


This knicker style completely covers the hips and bottom. Several different versions exist, however, the sportier/sexier version with a g-string style gusset or with interesting cut-out detailing are most popular.



A variation of a corset, with soft bones running down to the waist/hip line of the body. It highlights the breasts with the use of underwired cups to offer support.

Particularly suitable for those who want the support/control over the tummy, or are looking for increased fullness in the bust with a slimmer waistline.


Bodysuits are extremely versatile, they can be sheer or see-through, and therefore worn as inner or outerwear. The body can have a variety of leg lines, shapes and cut-outs within the pattern. The cups can either be non-wired or wired to accentuate the bust.

Suspender Belt

This item is a band that goes around the waist with pieces of elastic hanging down with suspender clasps on the ends to attach to stockings.

The waist can either be a single piece of elastic/fabric or can be a fully shaped garment constructed with a matching fabric to compliment the collection it forms part of.