Size equivalents:

14 = Bust 32”, Waist 26.5”, Hips 35”
16 = Bust 34”, Waist 28”, Hips 37”
18 = Bust 36”, Waist 30”, Hips 39”
20 = Bust 38”, Waist 32”, Hips 41”

These are the standard sizes on most Minerva and Columbia patterns in the 1930’s and 40’s