Wheel-size guide

Kids, BMX, MTB, road

Bike Wheel Size Chart

Use this bike wheel size chart when the bike is sold by wheel diameter instead of frame size. A bicycle wheel size chart is most important for kids bikes, BMX bikes, folding bikes, and mountain bike wheel choices such as 27.5 or 29 inches.

Data reviewed: 2026-05-18

Find your size
Use measurements to narrow the chart to one or two likely sizes.
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Model geometry is a reference check; sizing comes from the available size chart rows.

Enter your measurements to see your recommended size, backup size, confidence, and why it fits.

Sizing notes

Read the chart, then check the bike.

Kids bike wheel size is not frame size

Kids bikes are usually sold by wheel diameter. A 16 or 20 inch bike describes the wheel, while lowest saddle height, inseam, and brake reach decide whether the child can control it.

A 20 inch bike has different meanings

A 20 inch bike can be a child's bike, a youth BMX, or an adult BMX wheel standard. Compare rider height, top tube length, and intended use before choosing.

Adult road bikes usually use 700c wheels

For most adult road, gravel, and hybrid bikes, 700c is the common wheel label. Frame size, stack, reach, and standover decide fit more than the wheel label.

Mountain bikes use wheel size for handling

Mountain bike wheel size affects rollover, acceleration, and standover. A 27.5 or 29 inch wheel choice still needs the frame size to match the rider.

Bicycle wheel size chart

Common wheel-size labels and the fit checks that matter before buying.

Size

12 inch

Height

2'10"-3'4" / toddler

Inseam: Balance bike or first pedal bike

Size

16 inch

Height

3'4"-4'0" / young child

Inseam: Check lowest saddle height and brake reach

Size

20 inch

Height

4'0"-4'8" / child or BMX

Inseam: 20 inch bike can mean kids bike or BMX wheel

Size

24 inch

Height

4'6"-5'2" / youth

Inseam: Confirm inseam before moving to adult XS

Size

26 inch

Height

4'10"-5'6" / youth or adult

Inseam: Older MTB, cruiser, folding, or compact adult fit

Size

27.5 / 29 inch

Height

adult MTB

Inseam: Choose by frame geometry, terrain, and handling

Size

700c

Height

adult road, gravel, hybrid

Inseam: Wheel size is standard; frame size decides fit

FAQ

Short answers for choosing a size before purchase.

How do I use a bike wheel size chart?

Use the wheel label to understand the bike category, then check rider height, inseam, saddle height, and frame fit before buying.

What does a 20 inch bike mean?

A 20 inch bike usually refers to wheel diameter. It can describe a kids bike, youth BMX, or adult BMX wheel, so check rider height and top tube length.

Is kids bike wheel size based on age or height?

Use both as a first pass, but height, inseam, lowest saddle height, brake reach, and confidence decide the final kids bike wheel size.

Is 700c a bike size?

700c is a wheel-size label used on many adult road, gravel, and hybrid bikes. It does not replace frame sizing.