Men's sports jackets come in a variety of sizes to fit men of various builds. However, many suit shops will alter a sports jacket to ensure an exact fit for the man who purchased it. That means the size listed on the tag may not be the actual size of the jacket. However, you can learn how to determine the size and sleeve length of a sports jacket to see if it will work for you.
Note the chest of a sports jacket, because this is the measurement that determines the size of the jacket. The chest is just below the collar, but just above the buttons on a sports jacket.
Measure the chest on your sports jacket in inches, using a tape measure to find the size of the jacket. If you must measure in centimetres, divide the total centimetres by 2.54 to obtain the correct number of inches.
Record the number of inches around the sports jacket is in the chest. This is the size of a sports jacket.
Find the top of the sleeves on your sports jacket. The sleeves begin where your neck meets your shoulders.
Measure the length of your sleeves by using a tape measure. Place one end of the tape measure at the beginning of the sleeve and measure straight down the sleeve to the cuff. Bend the sleeve slightly at the elbow for the most accurate measurement.
Note the number of inches from the beginning of the sleeve to the cuff. That is your sleeve length. If you measured in centimetres, divide that number by 2.54 to convert it to inches.
Remember that sleeve length is one of the easiest alterations to make on a men's sports jacket. If you have a good fit in the chest and in the shoulders, a tailor can take in the sleeves if they are too long. Your sports jacket sleeves should be short enough to show about a half-inch of cuff from your shirt.