Choosing The Right Size:

Adult bike sizes are normally referenced by frame size. Children’s bikes are usually referenced by wheel size.
A frame is measured from the top of the seat tube (where the seat post fits into the frame) down to the centre of the bottom bracket axle (the axle which carries the pedal cranks).  
With the correct frame size you should be able to sit on the saddle with your feet on tip-toes touching the ground on either side, and you must be able to reach the handlebars comfortably.

It is sometimes worth considering a smaller frame with the saddle raised slightly in order to obtain a more comfortable reach.

The sizing charts below give a guide to bike sizes against inside leg measurements. The correct way to measure your inside leg is from your crotch to the floor making sure that your feet are flat on the ground.

Adult size guide by frame size to inside leg measurement:


Frame Size      Inside Leg Range
 14"                    24"-29"
 15"                    25"-30"
 16"                    26"-31"
 17"                    27"-32"
 18"                    28"-33"
 19"                    29"-34"
 20"                    30"-35"
 21"                    31"-35"
 22"                    32"-37"
 23"                    33"-37"

Youth/Teenage by frame size to inside leg measurement:


Frame Size      Inside Leg Range
 14"                    24"-29"
 16"                    26"-31"
 17"                    27"-32"
 19"                    29"-34"
 20"                    30"-35"


3 to 9 years by frame and wheel size to inside leg measurement:


Frame Size     Wheel Size     Typical Age     Inside Leg Range
 N/A                     12"             3+ Years           13-16"
 N/A                     14"             4+ Years          16-20"
 11"                       18"             6+ Years          19-22"
 11"                       20"             7+ Years          20-23"
 13"                       20"             7+ Years          22-25"
 14" sus                 24"             9+ Years          24-27"