There’s two white mark on the inside, please see photos.

Measurements:

• Collar to shoulder: 10.25"
• Shoulder - Seam to seam: 20.25"
• Chest - Pit to pit: 24"
• Waist: 23"
• Hip: 25"
• Front length: 31.5"
• Shoulder to sleeve: 25.75"
• Pit to sleeve: 16"
• Upper arm width: 8"
• Sleeve hole width: 5.75"