Hello Gareth, nice to hear the Diary is helping you.
16ft or 192in includes the 1in boards, so it’s 190in.
Allow 5in from one end for the first row of potatoes, and 5in from the other end for the first row of lettuce.
That should add up. See also http://www.charlesdowding.co.uk/no-dig-growing/homeacres/ for photos of the plantings. It’s my experimental beds last year 2016.
