From the Registration guidelines on the AHS website:
"Imagine a wire circle that is just large enough for the average or typical sized flower to pass through without touching. The diameter of the circle in inches will be the diameter of the flower. If you prefer, use a ruler and measure from tip to tip at the widest point and this will be the diameter. The main thing to remember is to measure as naturally standing - do not uncurl recurved flowers for the measurement. The second thing to remember in recording this measurement is that there are four categories of bloom size in daylilies:
1. Miniature— less than 3" in diameter
2. Small — 3" or more but less than 41⁄2" in diameter
3. Large — 41⁄2" or more but less than 7" in diameter
4. Extra Large — 7" or more in diameter
For instructions on measuring Spider daylilies, see the discussion under "FORM". Increments less than 1/8 inch may be rounded, except where it would cause confusion for show classification."
https://daylilies.org/wp-conte...
