Proper Size for a Cane
The first thing I should say is that you should consult a doctor for a proper fit. That being said, there are two common ways to find the proper fit for a cane.
One way is to stand up straight with your arms hanging at your sides. Your arms should be slightly bent (about 20 degrees). The cane should come up to the crease in your wrist.
The second way is to turn the cane upside down and put the handle of the cane on the ground beside your foot. The cane should come up to the top of your hip bone. (I put the cane upside down so I can mark the bottom of the cane where it needs to be cut.)
Since these canes are made from wood, they can easily be cut shorter. You can slide the rubber tip off the bottom of the cane, cut the cane and slide the rubber tip back on. If you need to shorten your cane, cut it a little longer than what you think is the correct size and try that for a while. Then, you can cut it shorter again if you want. However, be careful when you cut a cane because it is difficult to make it longer after you cut it.
If you lean heavily on a cane, the cane should be straight up and down so it doesn't break. If you use a cane just for balance, you can use a longer cane because you use the cane without leaning heavily on it.
These are the guidlelines for the height of a cane I usually use when I make a cane:
A 33 inch cane for a person that is 4'8" to 4'11"
A 34 inch cane for a person that is 5'0" to 5'3"
A 35 inch cane for a person that is 5'4" to 5'7"
A 36 inch cane for a person that is 5'8" to 5'11"
A 37 inch cane for a person that is 6'0" to 6'3"
A 38 inch cane for a person that is 6'4" to 6'7"