Suit coats and sport coats are similar in style, but they vary in how they are worn, when they are worn and the materials used to make them.
The biggest difference between these two styles of men’s coats is how they are worn. Suit coats are worn as part of a suit, with matching pants made out of the same material and in the same style. Sport coats are worn on their own and can be paired with a variety of pants.
Suit coats are far more formal as they are part of a full suit. These are worn in professional and formal settings, whereas sport coats are for more casual occasions.
Suit coats are nearly always made of either wool or cotton, depending on the season. While sport coats are often made of these materials, they are more typically made of other materials such as camel hair, tweed or corduroy.
Because sport coats are more casual, they can appear in brighter and more unusual colors, while suit coats are most often found in conservative colors, such as black or gray.
Suit coats are almost always worn with a tie, but sport coats are often worn without a tie.