\how to measure armhole length

hi everyone

I am shaping armholes and it says to cast off 2 stitches beginning next 6 rows then to continue even until armhole measures 5 inches. Where do begin to measure? From the very first cast off or at the point where I begin to knit even?

Debbie

Measure up from the same row you cast off the first st in, don’t measure around the curve.

Thanks Suzeeq