Plus Size Semi Formal Dresses: What It Means and 7 to Buy

The card says semi-formal, the wedding is a few weeks off, and you are not sure whether that means the floor-length gown in your wardrobe or the wrap dress you wear to work. The dresses you like stop two sizes short of yours, and the ones in your size look like something for the office. Below is what semi-formal means in practice, then seven dresses sold in plus sizes, each with the range its listing sells, the price, and what is wrong with it.

The quick answer

A dressy dress from knee length to tea length, in a fabric with some occasion to it, is the working answer for a semi-formal wedding; on this guide’s working definition, a gown is more than asked for, and a plain office dress is less.

Dress	Sizes sold	Price	Length and sleeves
Kiyonna Vita Midi Cocktail Dress	0X (10-12) to 5X (30-32)	$168	Knee length, sheer 3/4 sleeves
Kiyonna Mademoiselle Lace Cocktail Dress	0X (10-12) to 5X (30-32)	$168	Midi, 3/4 sleeves
London Times Laurenda Beaded Pearl Illusion Mesh Midi	Curve 14w to 24w	$138	Midi, long sleeves
Karen Kane Plus Size V-Neck Scallop Lace Dress	0X to 3X	$158	Knee length, 3/4 sleeves
Adrianna Papell Plus Size V Neck Metallic Jacquard Fit And Flare Midi Dress	Plus 14 to 26	$219	Midi, sleeveless
Alex Evenings Plus Soutache Scoop-Neck Jacket Dress	14W to 24W	$269	Tea length, jacket with 3/4 sleeves
BloomChic Floral Embroidery Sheer Mesh Bell Sleeve Midi Dress	10/M to 30/6X	$69.90	Midi, sheer long sleeves

What semi-formal means on a wedding invitation

The phrase has an older, stricter meaning and a newer, looser one. Semi-formal wear, in Wikipedia’s words, is “a grouping of dress codes indicating the sort of clothes worn to events with a level of formality between informal wear and formal wear.” The older reading is strict: “The traditional interpretation for men is black tie for evening wear and black lounge suit for day wear, corresponded by either a pant suit or an evening gown for women.” The same entry then adds: “In more colloquial, modern formulations, semi-formal has been defined closer to what is traditionally considered ‘informal wear’.” And informal wear, the next step down, is defined there by a “cocktail dress or trouser suit for women.”

That is the gap between a gown and a cocktail dress. This guide’s working definition for a wedding card that says only “semi-formal”: a knee-length to tea-length dress in a dressier fabric (lace, velvet, jacquard, beading or embroidered mesh), or a dressy trouser outfit; not a floor-length gown unless the card says black tie, and not the plain dress you wear to work.

Time of day is the other half: in the same Wikipedia entry, the choice between day and evening semi-formal “has traditionally been defined by whether the event will commence before or after 6:00 p.m.” Our reading of that for a wedding: if the ceremony or reception starts after six, pick from the dressier end of the list below.

If the card says cocktail attire rather than semi-formal, what cocktail attire means covers that code on its own; if it says black tie, the dresses by code are in plus size wedding guest dresses.

The seven

Kiyonna Vita Midi Cocktail Dress

$168 as of 28 Sep 2026 · 0X (10-12) to 5X (30-32) · View it on the brand’s site →

Flocked dot mesh with an illusion sweetheart neckline, slim 3/4 sleeves and a gathered knee-length skirt, fully lined except the sleeves. The listing calls it “this semi-formal dress” and lists a wedding guest outfit among its uses, and gives the 1X at 43 3/4 inches to the hem. On Kiyonna’s size chart, 5X is a 61 to 66-inch bust and a 66.5 to 71.5-inch hip. It suits a daytime or early-evening wedding where you want a print that still reads as dressed up.

Drawbacks: one colour only (Noir Dot), dry clean only, and the sleeves are unlined sheer mesh, so they give no warmth.

Kiyonna Mademoiselle Lace Cocktail Dress

$168 as of 28 Sep 2026 · 0X (10-12) to 5X (30-32) · View it on the brand’s site →

Scalloped lace in a fit and flare midi with 3/4 sleeves, made in the USA, in six colours: Onyx, Navy, Berry Bliss, Emerald Green, Pinot Noir, and Black and Nude. The listing sells it for “day or evening, formal or semi-formal” and gives the 2X at about 45 inches from the shoulder to the hem. It is the pick if you want lace and a choice of colour.

Drawbacks: the care line says dry clean only (a brand answer in the listing’s Q&A says cold hand washing is safe), and the 3/4 sleeves are about 15 1/2 inches long, not full length.

London Times Laurenda Beaded Pearl Illusion Mesh Midi

$138 as of 28 Sep 2026 · Curve 14w to 24w · View it on the brand’s site →

Sold on Maggy London’s site under the London Times label: a sheer, pearl-embellished long-sleeve top over a structured skirt with a flounce hem, in a scuba knit, in navy, black or ivory. The store tags it Semi-Formal. The Curve sample, an 18W/2X, measures 43 3/4 inches from the back neck to the hem. It is the one for an evening wedding if you want long sleeves and some shine, and it is hand wash rather than dry clean.

Drawbacks: the Curve run stops at 24w; its Curve size chart did not come through as text when read, so check it on the listing; the $138 is the Curve price (Standard sizes are $128); only the bodice is lined.

Karen Kane Plus Size V-Neck Scallop Lace Dress

$158 as of 28 Sep 2026 · 0X to 3X · View it on the brand’s site →

Stretch floral lace (60 percent nylon, 32 percent rayon, 8 percent spandex) over a lining, with a V-neck, 3/4 sleeves and a side zip, made in the USA, in black or navy. The 2X is 42 3/4 inches long. A simple lace sheath that works for a semi-formal wedding and again for a dinner afterwards, and it is hand wash.

Drawbacks: the plus run stops at 3X, which Karen Kane’s chart gives as a 51-inch bust, 43-inch waist and 53-inch hip; the listing describes a “body-skimming silhouette”, so it is not the cut for room through the middle.

Adrianna Papell Plus Size V Neck Metallic Jacquard Fit And Flare Midi Dress

$219 as of 28 Sep 2026 · Plus 14 to 26 · View it on the brand’s site →

A hunter-and-gold metallic jacquard in a botanical pattern, with princess seams, a pleated high-low skirt, a ruffle-trimmed V neckline and side pockets; 38 inches from the top of the shoulder to the hem. Adrianna Papell’s plus chart puts 26W at a 54-inch bust and a 58.5-inch hip. Metallic jacquard makes it our evening pick of the seven, for a wedding that starts after six.

Drawbacks: sleeveless; the listing marks the fabric “No Stretch”; dry clean; size 22 was sold out on 28 September 2026.

Alex Evenings Plus Soutache Scoop-Neck Jacket Dress

$269 as of 28 Sep 2026 · 14W to 24W · View it on the brand’s site →

A tea-length dress with a scoop neck and a mock open jacket trimmed in soutache, with three-quarter sleeves, so the arms are covered without a separate cover-up. The 14W measures 48 1/2 inches from the top of the shoulder to the hem, and the stretch level is listed as moderate. It suits a church ceremony, or a guest who wants the arms covered all day.

Drawbacks: the highest price of the seven, one colour only (Brush Peri), and the size chart did not come through as text, so check it on the listing before choosing a size.

BloomChic Floral Embroidery Sheer Mesh Bell Sleeve Midi Dress

$69.90 as of 28 Sep 2026 · 10/M to 30/6X · View it on the brand’s site →

Black embroidered mesh with ruffle sleeves, a V-neck, side pockets and an elastic, pull-on waist, sold as “Tailored for mid and plus-size women.” The listing prints both a body chart (6X is a 61.8 to 65.7-inch bust and a 65.7 to 70.1-inch hip) and a garment chart, which runs from 46.5 inches long at M to 52 inches at 5X and 6X. The lowest price of the seven, at about half the next cheapest.

Drawbacks: black only; the mesh sleeves are sheer; at 46.5 inches long even in M, check the length against your height before ordering.

How to choose

• Your bust is over 56 inches: Kiyonna’s 4X and 5X (56.5 to 66 inches on its chart) or BloomChic’s 4X to 6X (53.9 to 65.7 inches on its body chart). Karen Kane’s 3X is a 51-inch bust and Adrianna Papell’s 26W a 54-inch bust, so check those two against your bust, waist and hip before ordering.
• The wedding starts after six: the Adrianna Papell jacquard, the Laurenda or the Mademoiselle in a dark colour.
• You want your arms covered: the Laurenda has long sleeves and the BloomChic sheer long ones; the Vita (sheer), Mademoiselle, Karen Kane and the Alex Evenings jacket have 3/4 sleeves. The Adrianna Papell is sleeveless.
• You would rather not pay for dry cleaning: the Laurenda, the Karen Kane and the Alex Evenings list hand washing on their care lines; the Mademoiselle’s care line says dry clean only, though a brand answer in its Q&A says cold hand washing is safe.

Before you order

• Check the length for your height. Each listing measures a different size from a different point (back neck, top of shoulder, or “Full Length to Hem”), so compare the figure to a dress you already own, measured the same way.
• Order early enough to exchange. Read each store’s returns page before paying.
• Check your colour is in stock in your size, not just the style: on 28 September 2026 the Adrianna Papell 22 was already gone.

Where these numbers come from

Sizes, prices, lengths, fabrics and quoted phrases are copied from each brand’s product listing and size chart, read on 28 September 2026, in US dollars, and the definitions are quoted from Wikipedia’s entries on semi-formal and informal wear. The working definition of semi-formal and the before-or-after-six advice are our reading of those entries.

Frequently asked questions

What does semi formal mean for a wedding?

Dressier than office clothes, less formal than black tie. This guide's working definition for a wedding card is a knee-length to tea-length dress in a dressier fabric such as lace, velvet, jacquard or beading, not a floor-length gown and not a plain day dress. On Wikipedia's semi-formal wear page the traditional reading is black tie in the evening for men, with a pant suit or evening gown for women, and modern use sits closer to informal wear, which Wikipedia's informal wear page gives for women as a cocktail dress or trouser suit.

Does the time on the invitation matter?

Yes. Wikipedia's entry says the choice between day and evening semi-formal has traditionally turned on whether the event starts before or after 6:00 p.m. Our reading: after six, take the dressier fabric, such as the Laurenda's pearl-beaded mesh or the Adrianna Papell jacquard; before six, a printed or lighter piece like the Vita's flocked dot mesh.

Which of these semi formal dresses go to the largest sizes?

Kiyonna's Vita and Mademoiselle run to 5X (30-32), a 61 to 66-inch bust on Kiyonna's chart, and the BloomChic dress runs to 30/6X, a 61.8 to 65.7-inch bust on its listing's body chart. Karen Kane's lace dress stops at 3X, which its chart gives as a 51-inch bust.