“Smart casual” is the most common dress code in travel and the least understood. It appears on hotel bar menus, restaurant booking confirmations and resort welcome letters, and it means different things in London, Miami and Milan. There is still a reliable formula that keeps you right in almost every case.

The Formula

One element with structure, one element that is relaxed, and good shoes. A tailored jacket with dark jeans. A silk blouse with wide-leg trousers. A fine knit with a midi skirt. Structure keeps it smart; the relaxed piece keeps it from looking like the office.

What Usually Does Not Count

• Athletic wear, including expensive athleisure.
• Flip-flops, slides and running shoes.
• Shorts in the evening, even at warm-weather resorts.
• Baseball caps and anything with large logos.

Shoes Make the Call

Polished shoes are often the deciding factor at the door. Loafers, leather ankle boots, clean minimal leather sneakers in some cities, and low heels all work. If in doubt, choose leather.

Read the Room by City

Smart casual in a resort town can mean linen and sandals; in a European capital it leans closer to tailored. Grand old hotel bars often expect a jacket for men in the evening. If the hotel has a stated policy, it will usually be on its website or with the concierge, and it is worth a quick look before you go down.

The Safe Default

Dark trousers or jeans, a crisp shirt or fine knit, a jacket you can take off, and leather shoes. It works for a cocktail in the lobby, dinner in the restaurant and a nightcap afterward.

Shop the Edit

• Theory Slim-Fit Wool Blazer in Deep Navy, Saks Fifth Avenue
• Khaite Danielle Straight-Leg Jeans, Saks Fifth Avenue
• Alas Silk Button-Up Shirt in Milk White, Nordstrom
• Vince Wool-Blend Tailored Wide-Leg Pant, Vince
• Tod’s Gommino Suede Loafer in Tabacco, Saks Fifth Avenue
• Common Projects Achilles Low Sneaker, FWRD