How to Check the Measurement

Please note:

Find a jacket to measure, which suit you well. NOT MEASURE YOUR BODY. 

1. Measure the CHEST.

Put the jacket on the table. Make it flat, now you can measure the it. From armpit to armpit.
Use your hands pull both sides of the garment and the ruler straight at the same time. Don't release your hands! To make the measurement correct.
P.S.: Clothes can't be wrinkled. Otherwise, the measurements won't be accurate.

2. To measure the sleeve. The sleeve isn't straight. It's curve. So, please measure it like below drawing.

3. To measure the shoulder. 

Don't measure in straight. It's also curve. Please measure like drawing.