Black Tie Optional for Women in Their 30s and 40s

For black tie optional in your 30s and 40s, wear a long gown, a midi evening dress that falls to the lower calf, or a floor length evening jumpsuit, in a deep color. Start with the Iris Off-Shoulder Maxi Gown in Anthracite ($770). In daylight the metallic finish looks almost black, and under candlelight it looks warmer. It measures 58 inches from the back of the neck to the hem on a size 2. Luna prints that number on the page, so you can measure from the back of your own neck and see where the hem falls.

What is the difference between black tie optional and cocktail attire for women?

Black tie optional is formal eveningwear with a choice. Most men will be in tuxedos and most women in long gowns. A midi evening dress that reaches the lower calf is also welcome, and so is a floor length evening jumpsuit. Cocktail attire is a step down. It usually means a dress at or just below the knee.

The fabric matters as much as the length. Metallic finishes, lace, chiffon and woven jacquard read as evening, while plain cotton jersey and linen read as day. This guide covers black tie optional only. When an invitation says black tie with no other word, expect floor length and ask the host before you choose anything shorter.

What to wear to black tie optional in your 30s and 40s

In your 30s and 40s, you will see this code on several kinds of invitations. It can be a wedding in June, a partner’s company dinner in December and a friend’s 40th at a hotel. A piece you buy for 1 of them should cover the other 2. Choose for your busiest season, and decide whether you want your arms covered for a ceremony.

Long gowns and a floor length jumpsuit

• The Iris has a draped off-shoulder neckline across the collarbone and a tiered sheer waist band set with small dark crystals. The full A-line skirt is lined. It is 97% polyester and 3% elastane, and it is machine washable on a gentle cycle. Over a wedding, a company dinner and a birthday, the $770 gown comes to about $257 an evening.
• The Rebeka Long Dress in Plum ($670) gives you both options if you are unsure about sleeves. Its sheer chiffon drape sleeves attach at the shoulder and come off. Wear them for a November ceremony and leave them at home for a summer reception. The gown has a soft V neckline, an empire bodice and a waist belt. The A-line skirt reaches the ankle, 55 inches on a size 2.
• For an evening with dancing, choose the Alis Off-Shoulder Metallic Gown in Bordeaux ($770). It has a folded off-shoulder neckline and fine vertical pleats in a metallic fabric. A front slit lets you take stairs and dance. The fishtail hem finishes at the ankle, 56 inches on a size 2.
• If you would rather wear pants, the Jody Lace Jumpsuit in Black ($550) has a sleeveless European lace bodice and a sheer illusion yoke. A slim belt with a buckle sits above wide legs to the floor.

Midi evening dresses

• The Lucy Jacquard Midi Dress in Midnight Blue ($695) has a sweetheart V neckline and sheer 3/4 sleeves. A sheer band is set into the flared skirt near the hem. It reaches mid calf, 46 inches on a size 2, and it is fully lined. You can wear it from a daytime ceremony through an evening reception.
• For a summer evening, the Nela Midi Dress in Black ($695) has spaghetti straps, a V neckline and a pleated skirt in a textured black weave. It is also 46 inches on a size 2. The weight suits a warm night outdoors.

Gowns, midi dresses and jumpsuits for this code are together in black tie optional outfits. Our longer guide to black tie optional for women covers fabrics and lengths in more detail.

What to wear over it, by season

Between October and March, we would put the Lucy Wool Coat with Faux Fur Collar in Black ($910) over these pieces. It is double breasted in long fiber wool and fitted at the waist. The skirt flares to the knee, 40 inches on a size 2. Over the 58 inch Iris gown, about 18 inches of skirt show below the coat. Over the 46 inch Lucy midi, about 6 inches show. The faux fur collar detaches, and without it you can wear the coat to the office. Our guide to the winter coat in your 40s covers coats that also work for travel.

In the warm months, bring a wrap for an air conditioned room.

What to avoid

At a wedding, leave white, ivory and champagne to the bride. Save the hem above the knee for a cocktail party. Office pants and daytime cotton do not meet the code. Try a floor length jumpsuit on with your shoes before the event.

What shoes and bag go with black tie optional attire?

Wear a heel you can stand and dance in. Choose the shoe before you settle the hem. The Jody jumpsuit page asks you to check the length against the heel you plan to wear. A floor length leg should clear the floor by about half an inch. Our model is 5 foot 9 and wears a size 2, so compare your own height before you decide. Carry a small evening clutch, and keep 1 metal tone across the bag, the earrings and the buckle.

A short checklist

• Read the invitation for the word optional.
• List the other events on your calendar this season.
• Choose long or midi, then sleeves or no sleeves.
• Measure from the back of your neck to the floor and compare it with the listed length.
• Plan the coat with the outfit in the cold months.

For a wedding with this code, read wedding guest dresses in your 30s and 40s. When the invitation says cocktail, read our cocktail dress guide for your 30s. For a benefit evening, see what to wear to a charity gala in your 30s and 40s. Every other event is on the Shop by Occasion page.

Questions about black tie optional in your 30s and 40s

Does a black tie optional dress have to be floor length?

It does not. A long gown is the safe choice, and a midi evening dress that falls to the lower calf is also accepted. A dress that stops at or above the knee belongs to cocktail attire.

Can a woman wear pants to a black tie optional event?

She can. Wear a floor length evening jumpsuit, or wide leg pants in an evening fabric with a dressy top. The Jody Lace Jumpsuit in Black has a lace bodice and wide legs. Office pants with a daytime blouse do not meet the code.

Where can I buy a black tie optional dress with sleeves?

Luna Fashion House makes the Lucy Jacquard Midi Dress in Midnight Blue with sheer 3/4 sleeves. The Rebeka Long Dress in Plum has sheer drape sleeves you can remove. Both are in the black tie optional collection, with free US shipping.

Can I wear a midi dress to a black tie event?

At a black tie optional event you can, when the midi falls to the lower calf and the fabric reads as evening. When the invitation says black tie with no other word, ask the host before you choose a midi.

What should I wear to a black tie optional wedding in my 30s or 40s?

Wear a long gown for an evening reception with dancing. A midi evening dress suits a ceremony and a seated dinner. Choose a deep color and leave white and ivory to the bride.

Does Luna ship free, and can I return a piece?

Shipping to any US address is free. Orders ship from California and arrive in 2 to 5 days, and you can return any order within 30 days with no questions asked.