I agree with the others' statements. The quoted plant height should never include the pot height. Whenever I sold extra seedlings in the past, I always measured just the plant, rounding the measurement down to the nearest inch, and always stating that the measurement is just the plant's height, not including the pot's height. I would also measure from the base to the top of the stem, not to the height of the top leaf. Measuring a floppy plant is a little trickier; I tend to measure how high it stands, not how long it is. So, for instance, if the plant has a 12" long main stem that flops over and only stands 6" tall, then I would say it is a 6" tall plant.