Measuring arm holes on pattern

Hello, making a child’s vest, first time garment. Working armholes and have completed the bottom shaping. Next instruction is “work even until armhole meas about 5 inches”…
Question - am I measuring 5 inches of the ‘even’ part, or along the curve including the shaping at the bottom?
I am holding it up to my little guy but can’t imagine how much space the ribbing around the armhole will add later on

much thanks, I am going to sit and look at this a little longer…

Using a ruler, measure from the outer edge where you started the decrease upward in a straight line