Formal Dress Guide
Formal dresses: a guide to styles, fabrics and fit
Formal dresses are the evening gowns and dressy shorter styles worn to weddings, proms, quinceañeras and black-tie events. Formal Dress Guide explains what each dress code asks for and how silhouette, neckline, fabric and length change a dress, before you shop.
On this page
Find your dress
- Bridesmaid dressesMatching or mixed, fabrics for every body, and who pays.
- Prom dressesLong or short, school rules, corsages and names abroad.
- Quinceañera dressesThe ball gown, the tiara, the shoes and the court.
- Mother of the brideWho chooses first, colours to avoid, the right length.
- Flower girlsMini versions of the bride's dress that children can wear.
- Wedding dress silhouettesBall gown to mermaid, waistlines and maternity.
- NecklinesSweetheart, bateau, halter and seven more, drawn.
- FabricsChiffon, satin, tulle, organza and lace compared.
- Lengths and trainsHemlines from mini to floor, trains from sweep to royal.
- How to measureBust, waist, hips and hollow-to-hem, and choosing a size.
- Veils and accessoriesVeil lengths, gloves, wraps, sashes and bouquets.
What “formal” means on an invitation
A formal dress is whatever the event's dress code asks for. Western dress codes were written mostly around men's clothes — tailcoats, dinner jackets — and the women's side follows the evening fashion of the day, so each code is best read as a level of formality. From the most formal down:
| Dress code | The dress | Worth knowing |
|---|---|---|
| White tie (full evening dress) | A full-length ball gown or evening gown, with long evening gloves | Jewellery, a tiara and a small handbag are optional, and a wrap or coat may go over the gown. Now kept for royal and state occasions, some balls and some weddings |
| Black tie | An evening gown or other fashionable evening wear | The range runs from just below the white-tie standard to a smart cocktail dress, which may be long or moderately short and need not be black |
| Cocktail (semi-formal) | A cocktail dress, usually worn with accessories | Anything from a little black dress to a short, plain evening gown, as long as it is worn with accessories; cocktail parties usually start in the late afternoon |
“Semi-formal” has two meanings In the traditional scheme white tie is the only full evening dress, so black tie itself counts as semi-formal, or “half dress”. The cocktail dress, meanwhile, is defined as the dress for semi-formal occasions, so the word can point either way. When a card simply says “formal” or “semi-formal”, it is fair to ask the hosts which they mean.
Six silhouettes behind almost every formal dress
The silhouette is a dress's outline: where it follows the body and where the skirt starts to stand away from it. Six shapes cover almost every formal and bridal dress. An evening gown can be any of them; a ball gown always has a fitted bodice and a full skirt, and it remains the most formal shape of all.
| Silhouette | The fit | Usually worn for |
|---|---|---|
| Ball gown | A fitted bodice and a full skirt that starts at the waist, held out by petticoats or layers of stiff tulle | White tie, black tie, formal weddings and quinceañeras: the most formal shape there is |
| A-line | Fitted above and around the hips, then widening gently to the hem like a capital A | Almost any formal event; it can be cut at any length, and is a popular wedding-dress shape |
| Sheath | A straight, fitted cut that follows the body, often with no seam at the waist | Cocktail and evening events; knee length for day, long for evening |
| Empire | A fitted bodice ending just below the bust and a long skirt that skims the body | Long, light evening and bridal dresses; a classic maternity shape since the 1790s |
| Trumpet | Fitted through the bodice and hips, flaring from about mid-thigh like the bell of a trumpet | Evening gowns and weddings: a fitted shape with more room to walk than a mermaid |
| Mermaid | Fitted from the bodice to the knee, then flaring at or below the knee into a fishtail | Evening gowns and weddings; the tightest fit here, so try walking and sitting in it |
Some of the names are older than they sound. The Empire line, with its bodice ending just under the bust, came into fashion in the late 18th century, but the name — after the First French Empire of 1804–1815 — was only coined in early-20th-century Britain. “A-line” was first used for a Paris couture collection in spring 1955. Trumpet and mermaid are the two most often confused: a trumpet flares from about mid-thigh, a mermaid only at or below the knee. The wedding dress silhouettes guide goes through each, with waistlines and maternity dresses.
Necklines: the shapes with names
The neckline is the top edge of a dress around the neck and shoulders. On a sleeveless or strapless formal dress it frames the face more than anything else, and most shapes come both with straps and in a strapless version. The names you will meet most often — the necklines guide draws each one:
| Neckline | The shape |
|---|---|
| Sweetheart | A curved, doubly scalloped edge like the top half of a heart |
| Strapless | No straps at all; the bodice is held up by its own fit, usually over an internal corset or boning |
| Off-the-shoulder | Lower than a boat neck, below the shoulders and collarbone, usually passing over the upper arms |
| Bateau (boat) | High, wide and nearly straight, running across the collarbones almost to the shoulder points |
| Halter | A V or scoop front with a strap that ties or fastens behind the neck |
| One-shoulder | A single edge cutting diagonally from one shoulder to under the other arm |
| V-neck | Two diagonal lines from the shoulders meeting on the chest |
| Square | Three straight edges meeting at right angles, the sides passing over the shoulders |
| Scoop | A curved U, its arms hanging on the shoulders |
| Illusion | A low, often strapless neckline with sheer fabric or lace above it |
Fabrics: drape, crispness and shine
Two questions decide which fabric suits a dress: does it drape against the body or hold its own shape, and is it shiny or matt? Most of these fabrics were first made of silk. Today they are also woven from polyester, nylon or rayon, which cost less and are more resilient; silk chiffon, for one, needs dry cleaning. The fabrics guide adds lace names and how to judge a swatch.
| Fabric | What it is | Where it works |
|---|---|---|
| Chiffon | A lightweight, sheer plain weave of high-twist yarns; floats and drapes, and frays easily | Overlays that make an evening gown look light and floating |
| Georgette | A sheer, dull-finished crêpe; springier and less lustrous than chiffon | Loose, flowing dresses rather than structured ones |
| Charmeuse | A light satin weave with a shiny face and a matt back; it clings and hangs | Bias-cut, fluid gowns; never full, flared skirts |
| Crêpe | A fabric of hard-twisted yarns with a crisp, crimped surface; silk, wool or synthetic | Sheath and column dresses with a matt finish |
| Satin | A weave rather than a fibre: long floating yarns give a glossy face and a dull back; it can snag | Evening gowns and ball gowns; heavy duchesse satin for structured bridal gowns |
| Lace | An openwork textile with a pattern of holes, made by hand or machine | Trim and overlays, and the sheer top of an illusion neckline |
| Taffeta | A crisp, smooth plain weave that holds its shape and does not drape | Ball gowns and wedding dresses |
| Organza | A thin, sheer plain weave with a crisp hand, stiff for its weight | Sheer layers that stand away from the body |
| Tulle | A fine, stiff hexagonal netting, often starched; most often polyester | Veils, wedding gowns, and petticoats that hold a skirt out |
Match the fabric to the shape A full ball-gown skirt is made in a fabric with body — satin, taffeta, organza — and held out by petticoats or layers of stiff tulle. Sheath, Empire and soft A-line dresses want fabrics that fall: chiffon, georgette, charmeuse.
Lengths and trains
A dress's length is named by where the hem falls: mini, above or below the knee, midi, tea, ankle and floor length, plus the high-low hem that is short in front and dips behind. Evening gowns are usually long. Their shorter drops are ballerina, from mid-calf to just above the ankle, and tea, which ends on the lower leg above the ankle. The lengths and trains guide draws every hem height.
A train is the back of the skirt extended to trail behind the wearer. Bridal wear names trains by how far they reach: a cathedral train measures up to 2.4 m (7.9 ft), and a royal cathedral 3 m (9.8 ft) or more.
Set the length with the shoes on A heel changes where a hem lands. Wear the shoes you will dance in for every fitting of a floor-length dress, and decide before the day how a train will be carried once the dancing starts. Veils have named lengths too: see wedding accessories.
Which dress for which occasion
- [Wedding dresses](/wedding-dress-silhouettes). White has been the dominant colour for Western wedding dresses since the mid-20th century, and “wedding white” takes in eggshell, ecru and ivory. Before the Victorian era a bride simply wore her best dress, in any colour; white spread among fashionable brides after a widely illustrated royal wedding in 1840. In Chinese and Indian traditions brides often wear red.
- [Bridesmaid dresses](/bridesmaid-dresses). Bridesmaids attend the bride, led by a maid or matron of honor if one is chosen; a junior bridesmaid is a girl too young to marry who is included anyway. Talk about cost early: bridesmaids now often pay for their own dresses, and in some American weddings each one is asked to spend US$1,700 or more once travel and parties are counted.
- [Flower girl dresses](/flower-girl-dresses). Flower girls are usually three to seven years old, and the outfit usually looks like a smaller version of the bride's dress. Families once provided it; most couples now expect the child's parents to pay.
- [Mother of the bride dresses](/mother-of-the-bride-dresses). By tradition she chooses first and tells the mother of the groom her colour and length, avoids white and near-white, and matches the formality of the wedding: floor length for a formal evening, tea or midi for a daytime one.
- [Prom dresses](/prom-dresses). Prom is the formal dance for graduating high-school students, called a “formal” or “grad” in Canada and a school formal or ball in Australia and New Zealand. Students dress formally, and a date traditionally gives a corsage.
- [Quinceañera dresses](/quinceanera-dresses). The quinceañera marks a girl's 15th birthday in Latin American cultures. She traditionally wears a long ball gown, chosen with her mother in her favourite colour, and a tiara; her court of honor typically has 7 to 15 pairs of damas and chambelanes.
How to choose a formal dress in five steps
- Read the dress code. White tie means floor length and evening gloves; black tie an evening gown or a dressy cocktail dress; cocktail a shorter dress with accessories.
- Pick the silhouette for how you will move. A ball gown or an A-line lets you walk, sit and dance freely; a mermaid holds the knees together, so try climbing a step in it.
- Match the fabric to the shape and the season. Structured fabrics hold a full skirt; draping fabrics suit sheath and Empire lines. Silk is softer and more delicate; polyester costs less and often survives a machine wash.
- Measure yourself, then read each maker's chart. Take your bust, natural waist and hips over the underwear you will wear, and the hollow-to-hem length from the hollow at the base of the neck straight down to where the hem should fall, in your shoes. Size labels follow no single standard and vary from maker to maker, sometimes by a full inch, so compare measurements, not size numbers — see how to measure for a dress.
- Fit it with the shoes and underwear you will wear. The hem, the neckline and the waist all move when they change.
Order early Many formal dresses are made to order, sewn only after you order and then shipped, and many need altering once they arrive. Ask for the production and delivery time in writing before you pay, and leave room for at least one fitting.
Frequently asked questions
What is the difference between a formal dress and an evening gown?
An evening gown is a long dress for formal evening occasions, in any silhouette. “Formal dress” is broader: whatever a formal dress code asks for, which at black tie can also be a dressy cocktail dress, and at white tie means a full-length ball or evening gown.
Is a cocktail dress formal enough for black tie?
Often, yes. Black tie for women ranges from just below the white-tie standard to something as simple as a little black dress, and a cocktail dress may be long or moderately short. For a very formal black-tie evening, a floor-length gown is the safer choice.
What is the most formal dress silhouette?
The ball gown: a fitted bodice with a full skirt that starts at the waist. It is the traditional choice for white tie, formal weddings and quinceañeras.
What is the difference between a mermaid and a trumpet dress?
Where the skirt flares. Both fit closely through the bodice and hips; a trumpet dress flares from about mid-thigh, a mermaid dress only at or below the knee, which makes it the more fitted of the two.
How long is a cathedral train?
Up to 2.4 m (7.9 ft) behind the wearer; a royal cathedral train is 3 m (9.8 ft) or more. A chapel train is shorter, 1.1–1.5 m (3.6–4.9 ft).
Formal Dress Guide is an independent reference. It does not sell, make, rent or alter dresses, has no connection with any designer, brand or shop, and has no connection with any earlier owner of this domain.