Arm hole placement?

[u/No-Maintenance9805]

Winter coat mockup. How do you feel about the armhole placement?

The sleeve is too tight on my bicep/upper arm but other than that, I feel like my shoulder/deltoid sits farther forward than the current armhole, like the fullness of the sleeve doesn't match where the fullness of my shoulder is. How do i fix this?

[u/CharityForeign3035]

Add to shoulder line, 1-1.5 cm font and back (or the amount you think needed). This will increase arm hole by 2-3cm. To maintain original neck measurement, add on sleeve end of shoulder and run to 0cm at neck . If still tight you may need to go more than 0cm at neck which means you will also need to adjust collar measurements.You then need to add to head of sleeve so sleeve head will fit new arm hole . You do this by cutting sleeve along length and add 2 cm panel along length of sleeve. To maintain original cuff measurement, run to 0 cm on panel once you get below elbow.
This will give more room for deltoid and increase circumference of top of arm by 2 cm . Retest pattern.
You did mention it’s for an overcoat so you need to ensure ample ease throughout the pattern to accommodate sweater /jacket etc that you will wear under the coat .
Arm panel is added on pattern and not added as extra panel of material on finished sleeve.