A well-fitted suit or sports jacket is an essential article of clothing, especially when you want to impress someone such as a new employer or your future in-laws. A good tailor takes precise measurements, but when a tailor is not available, you must take the measurements yourself and you will want to do so correctly. Having another person available to help with the measuring ensures that you get the proper calculations.
Start the cloth measuring tape from the center of your chest, under one arm, across the shoulder blades and back around to the center of your chest. Do not hold your breath while taking this measurement. This is your chest measurement.
Measure from the top of one shoulder across the back to the top of the other shoulder. If you are wearing a shirt, start the measuring tape at the seam at the top of the shoulder and arm and take it across the back to the opposite seam. This is your shoulder measurement.
Measure the length for the sports coat by placing the measuring tape at the top of the collar of your shirt, taking it down your back to where you wish the sports coat to end.
Measure the sleeve size for your sports coat by placing the measuring tape starting at the seam of your shirt at the shoulder and taking the tape down the length of your arm to the place on your wrist or hand you want the sleeve of the sports coat to end.
If your measurement stops at ½ inch, round the measurement off to the next full inch. A tailor can take a sports coat in if it needs it.