Short answer
For children, wheel size is the main sizing number, so height maps fairly neatly onto 12 to 24 inch wheels. For adults, wheel size mostly follows the type of bike, while height and inseam decide the frame size. The numbers below are approximate, and brands differ, so always compare with the maker’s own chart.
Kids: wheel size by height
| Wheel size | Approximate child height | Typical age (rough) |
|---|---|---|
| 12 inch | about 2’10” to 3’4” (86 to 102 cm) | 2 to 4 |
| 14 inch | about 3’3” to 3’8” (99 to 112 cm) | 3 to 5 |
| 16 inch | about 3’7” to 4’0” (109 to 122 cm) | 4 to 6 |
| 20 inch | about 3’10” to 4’5” and often a little taller (117 to 135 cm) | 5 to 9 |
| 24 inch | about 4’5” to 5’0” (135 to 152 cm) | 8 to 12 |
These ranges overlap on purpose. Inseam matters as much as height, since a child needs to reach the ground comfortably. The kids bike wheel size by age article goes into measuring and in-between cases. As a quick answer to a common question, a 16-inch bike usually suits children around 4 to 6, and a 24-inch bike usually suits older children and some smaller teens.
Teens and shorter adults
Between about 4’6” and 5’7”, riders often fit a 24-inch, 26-inch or 27.5-inch bike, depending on the bike and the frame size. A 26-inch mountain bike with an extra-small or small frame is a common match; see who a 26-inch wheel bike is for.
Adults: frame follows height, wheel follows bike type
Most adult road, gravel, hybrid and city bikes use 700c wheels (for tires specifically, see choosing a bike tire size for your height). Mountain bikes use 27.5-inch or 29-inch wheels, with 26-inch on older bikes. Within one wheel size, brands offer several frame sizes to cover different heights. A very rough frame guide for mountain bikes:
| Rider height | Common frame size | Wheel size often offered |
|---|---|---|
| about 5’0” to 5’4” | XS or S | 27.5 inch, sometimes 29 inch |
| about 5’4” to 5’8” | S or M | 27.5 inch or 29 inch |
| about 5’8” to 6’0” | M or L | 29 inch |
| 6’0” and taller | L or XL | 29 inch |
Frame sizes are not consistent between brands, so use this only to orient yourself. The mountain bike wheel sizing guide covers the 27.5 versus 29 choice in more detail.
How to measure your height and inseam
- Stand barefoot with your back against a wall and mark your height.
- For inseam, stand with feet slightly apart, hold a book or level snug against your crotch, and measure from the top of it to the floor.
- Compare both numbers with the brand’s chart, and check standover clearance on the bike itself.
If you fall between two sizes, many sellers suggest the smaller size for a sportier fit and the larger for comfort, but a test ride is the best check.
FAQ
How do you measure a bicycle?
Wheel size is the rim and tire diameter, such as 20 inch or 700c. Frame size is measured separately, usually along the seat tube in centimeters or inches. See how to measure your bike wheel size.
What size person is a 24 inch bike appropriate for?
Roughly older children and smaller teens, often those around 4’5” to 5’0”, though some riders are comfortable a little taller or shorter.
Where is the full list of sizes?
The bike wheel size chart lists every common wheel size alongside its rim diameter.