Because the two dress codes (and we use the term lightly) are so similar, the line between “business casual” and sharp casual is a blurry one. In fact, virtually all of the clothes that work for one will work for the other. It’s more about how you’re putting them together, plus a few exceptions that won’t work for work wear because they’re too flamboyant.
Broadly speaking: Business casual is less formal than suits, more formal than jeans and a T-shirt, and always work-appropriate. Sharp casual is less formal than suits, more formal than jeans and a T-shirt, and could be work-appropriate but doesn’t have to be. That’s pretty much your big difference there. The rest is all just details.
How to Make a Look Separate from Your Work Wear
To make a sharp casual look for social situations, take whatever existing business casual wear you have and ratchet up the colors and patterns a little. Dress shirts are a really good place to do this: if the colors and patterns are bold, the shirt pretty much says “not meant for corporate office work, no siree. Throw that on with the same slacks and jackets you wear to work and you’re good. Casual sports jackets in plaids, tweeds, and other aggressive patterns and textures can also look more easy-going and less like work wear, helping to set apart any outfit they’re worn with. Brightly-colored pants (not for the faint of heart) achieve the same results, a little more dramatically.
The key here is not to overdo it. A little color goes a long way. The same goes for patterns and even large-scale textures and weaves. Have one or maybe two pieces that “pop” a bit more than you could get away with at work. Keep the rest basically work-appropriate, and let those few statement pieces do the work of telling people that you haven’t just come from the office.
The Sharp in Sharp Casual
So what makes this any different from just plain ol normal clothes you wear to run errands or go about your daily life in?
Not much, really, except that most men don’t try to look attractive when they’re going about their personal business. If you’re making an effort — if your goal is for people to notice you and think “yeah, he’s dressed nicely” — then you’re probably in the realm of sharp casual, rather than just casual. That “sharp” usually manifests itself as extra pieces or a higher quality of clothing: a nice jacket thrown over an ordinary shirt, or dark, close-fitted jeans instead of faded work jeans.
A noticeable, visible, extra effort beyond the bare minimum that puts you up on a par with business casual, but doesn’t strictly adhere to a subdued office style that’s sharp casual in a nutshell.