There are few important measurements you need for making kimono.
The most important I'll always need (before even planning the design placement on the fabric) are:
yuki - from the center of the kimono to the end of the sleeve.
Measure the length from the center of your neck (the neck bone) to the wrist bone.
mitake - the length ot the kimono (from the shoulder top to the hem)
For women - your height
For men - from the base of your neck to your heel
Measure the circumference of your hips. Make sure you measure over the largest part of your buttocks - it's important to get the kimono width correctly.