Below are some measuring guidelines for the kilt length. If there are some large variations then you might want to check how you are measuring and try again. These can also vary depending on preference and body shape.
Height 5' 6" to 5' 7" = 22" to 22.5" kilt length
Height 5' 8 to 5' 9" = 23" to 23.5" kilt length
Height 5' 10" to 5' 11" = 24" to 24.5" kilt length
Height 6' to 6' 2" = 24.5" to 25.5" kilt length
Height 6' 3" to 6" 4" = 26" to 26.5" kilt length
Height 6' 5" to 6' 7" = 27" to 27.5" kilt length
The length of the kilt drop will vary and depend on how high you wear the kilt on your waist. It is also important to consider the kind of top you want to wear, whether it is a full-length or short-style jacket. The rule of thumb is that regular kilts are worn to the middle of the knee cap whereas military kilts are kept a little shorter and worn to the top of the knee cap. The best way to measure is to kneel down on the floor and have another person measure from where you intend to wear the kilt to the floor.
Where you wear the kilt on your waist is completely optional though the preferred method is to wear it around, or close to the navel. For this reason, the waist size on your kilt may be slightly different than the trouser's waist size. Measure your waist according to where you want to wear the kilt to ensure a good fit.