How to measure
Chest width
Lay it out
Lay the completely buttoned shirt flat on a table face up and position the arms in an upward direction.

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Measure across
Measure from the lowest point of the left armhole seem to the same point on the right.
Waist
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Measure across
Measure the distance between left and right edges at the when placing the tape measure between the 5th and the 6th button counting from the collar button.
Shoulders Width
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Measure across
Measure from the point where the left armhole seam meets the shoulder seam to its matching point on the right.
Back Length
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Top to bottom
Measure from the center of the collar base (where the back and collar seams meet) to the edge of the hem.
Sleeve Length
Stretch out
Straighten the sleeve to its natural position.
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Shoulder to cuff
Starting where the armhole and shoulder seams meet, measure to the end of the cuff.