Youth
Youth Bike Size Chart + Calculator
Find your bike size by height & inseam
Shopping with a youth bike size chart is the fastest way to get a bike your rider can control confidently. Start by measuring height and inseam; age is only a rough guide because kids grow at different rates.
Find your perfect size
Master size chart
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| Road frame size (cm) | Size label (approx) | Rider height (cm) | Rider height (ft/in) | Inseam (cm) | Inseam (in) |
|---|---|---|---|---|---|
| 47-49 | XXS / XS | 150-158 | 4'11"-5'2" | 70-73 | 27.6"-28.7" |
| 49-51 | XS / S | 158-163 | 5'2"-5'4" | 73-76 | 28.7"-29.9" |
| 51-53 | S | 163-168 | 5'4"-5'6" | 76-79 | 29.9"-31.1" |
| 53-55 | S / M | 168-173 | 5'6"-5'8" | 79-82 | 31.1"-32.3" |
| 55-56 | M | 173-178 | 5'8"-5'10" | 82-84 | 32.3"-33.1" |
| 56-58 | M / L | 178-183 | 5'10"-6'0" | 84-87 | 33.1"-34.3" |
| 58-60 | L | 183-188 | 6'0"-6'2" | 87-90 | 34.3"-35.4" |
| 60-62 | XL | 188-193 | 6'2"-6'4" | 90-93 | 35.4"-36.6" |
| 62+ | XXL | 193+ | 6'4"+ | 93+ | 36.6"+ |
| Size (letters) | Rider height (ft/in) | Rider height (cm) | Inseam (in) | Inseam (cm) | Traditional frame size (approx) |
|---|---|---|---|---|---|
| XS | 4'9.9"-5'1" | 145-155 | 27"-29" | 69-73 | ~33-36 cm (13"-14") |
| S | 5'1"-5'5" | 155-165 | 29"-31" | 74-78 | ~35-40 cm (14"-16") |
| M | 5'5"-5'9" | 165-176 | 31"-33" | 79-83 | ~40-47 cm (16"-18.5") |
| M/L | 5'8"-5'11" | 173-180 | 32"-34" | 81-86 | ~42-47 cm (16.5"-18.5") |
| L | 5'10"-6'2" | 177-188 | 33"-35" | 84-89 | ~44-52 cm (17"-20.5") |
| XL | 6'2"-6'5" | 188-195 | 35"-36" | 89-91 | ~49-56 cm (19"-22") |
| 2XL | 6'5"-6'8" | 195-203 | 36"-38" | 91-97 | ~56+ cm (22"+) |
| Height (ft/in) | Height (cm) | Freestyle: wheel | Freestyle: TT (in) | Race: category | Race: TT (in) |
|---|---|---|---|---|---|
| 12" | 11.5"-13" | Micro (<=4'4") | 15"-16.5" | ||
| 14" | 12.8"-15" | Micro (<=4'4") | 15"-16.5" | ||
| 16" | 14.5"-17" | Micro (<=4'4") | 15"-16.5" | ||
| 18" | 17"-18.5" | Mini (4'2"-4'10") | 16"-17.5" | ||
| 20" | 18"-20" (XS) | Junior (4'6"-5'1") | 17"-18.5" | ||
| 20" | 20"-20.25" (XS-Small) | Expert (5'0"-5'4") | 18.5"-19.5" | ||
| 20" | 20"-20.5" (Small-Medium) | Pro (5'3"-5'8") | 20"-20.5" | ||
| 20" | 20.25"-21" (Medium-Large) | Pro XL (5'7"-6'0") | 20.5"-21.25" | ||
| 20" | 20.75"+ (Large-XL) | Pro XXL (>=6'0") | 21.25"-22" |
| Height (ft/in) | Height (cm) | Size (letters) | Frame (in) | Frame (cm) |
|---|---|---|---|---|
| 148–158 | 4'10"–5'2" | XS | 13"–14" | 33–37 |
| 158–168 | 5'2"–5'6" | S | 15"–16" | 38–42 |
| 168–178 | 5'6"–5'10" | M | 17"–18" | 43–47 |
| 178–185 | 5'10"–6'1" | L | 19"–20" | 48–52 |
| 185–193 | 6'1"–6'4" | XL | 21"–22" | 53–57 |
| 193–198 | 6'4"–6'6" | XXL | 23"–24" | 58–61 |
| Frame size (cm) | Alpha (approx) | Height (cm) | Height (ft/in) | Inseam (cm) | Inseam (in) |
|---|---|---|---|---|---|
| 43/45 | XXS | 145-152 cm | 4'9"-5'0" | 67-71 cm | 26-28 in |
| 47/48 | XS | 152-168 cm | 5'0"-5'5" | 71-75 cm | 28-30 in |
| 51 | S | 168-173 cm | 5'5"-5'8" | 75-77 cm | 30-30 in |
| 54 | M | 173-178 cm | 5'8"-5'10" | 76-82 cm | 30-32 in |
| 56 | M/L | 178-183 cm | 5'10"-6'0" | 81-85 cm | 32-33 in |
| 58 | L | 183-188 cm | 6'0"-6'2" | 84-87 cm | 33-34 in |
| 61 | XL | 188-196 cm | 6'2"-6'5" | 87-91 cm | 34-36 in |
| Height (cm) | Height (ft/in) | Typical wheel | Typical size | Geometry guide (examples) | Inseam check |
|---|---|---|---|---|---|
| 135-155 cm | 4'5"-5'1" | 24" | "24" / Kids | TT ~20"-22" | Check geometry standover and aim for inseam - standover ~= 5 cm |
| 150-175 cm | 4'11"-5'7" | 24" | (varies) | TT ~20"-22.7" | Same: inseam - standover ~= 5 cm |
| 155-170 cm | 5'1"-5'7" | 26" | Short / S | Reach ~410-415; standover ~710-715 mm | Confirm with standover (2" rule) |
| 170-210 cm | 5'7"+ | 26" | Long / L | Reach ~425-435; standover ~710-715 mm | Confirm with standover (2" rule) |
| 160-185 cm | 5'3"-6'1" | 26" | (varies) | TT ~21"-24.5" | Same: inseam - standover ~= 5 cm |
| Frame size (cm) | Size label | Height (cm) | Height (ft/in) | Inseam (cm) | Inseam (in) | Frame size (in) |
|---|---|---|---|---|---|---|
| 47-49 | XS | 150-160 cm | 4'11"-5'3" | 65-70 cm | 26-28 in | 18.5"-19.3" |
| 50-52 | S | 160-170 cm | 5'3"-5'7" | 70-75 cm | 28-30 in | 19.6"-20.4" |
| 53-54 | M | 170-175 cm | 5'7"-5'9" | 76-80 cm | 30-31 in | 20.8"-21.2" |
| 55-56 | L | 176-182 cm | 5'9"-6'0" | 80-85 cm | 31-33 in | 21.6"-22.0" |
| 57-59 | XL | 183-190 cm | 6'0"-6'3" | 85-90 cm | 33-35 in | 22.4"-23.2" |
| 60-62 | XXL | 190-205 cm | 6'3"+ | 90-110 cm | 35-43 in | 23.6"-24.4" |
Shopping with a youth bike size chart is the fastest way to get a bike your rider can control confidently. Start by measuring height and inseam; age is only a rough guide because kids grow at different rates.
Measuring your height (3 steps)
- Set up: Take off your shoes. Stand with your back against a flat wall, looking straight ahead. Keep your posture tall; heels (and ideally hips/upper back) touching the wall.
- Mark it: Place a hardcover book or a set square on top of your head, level, and slide it until it touches your crown. Mark the wall where the bottom edge of the book meets it.
- Measure: Use a tape measure from the floor to the mark. Repeat 2–3 times and use the most consistent value.
Measuring your inseam (for bike sizing) (3 steps)
- Simulate the saddle: Barefoot, stand with your back to the wall. Put a book between your legs and push it up firmly into your crotch with pressure similar to a bike saddle. Keep the book level.
- Mark it: Without moving the book, mark the wall at the height of the book’s top edge (the edge pressing into your crotch).
- Measure: Measure from the floor to that mark. Repeat 2–3 times and use the average or the most repeatable value.
Tips and recommendations
Most youth bikes are sized by wheel diameter (typically 20, 24, or 26 inches), but fit still varies by brand and model even when the wheel size is the same. As a rule, do not buy one size up to grow into it; oversizing can reduce stability and confidence. Use the chart below to narrow your options, then confirm fit with quick checks: comfortable reach to the bars, safe stand-over clearance, and a seat height that matches your child’s skill level.
Youth Bike Size Chart: Choose 20, 24, or 26 by Height & Inseam
If you’re using a youth bike size chart, start with two measurements: height and inseam (crotch-to-floor). Age can help you guess, but it’s much less accurate than body measurements—and brands don’t size identically.
Step 1: Measure height and inseam (the quick method)
A reliable inseam measurement uses the book-between-the-legs method. Have your child stand against a wall (in socks). Place a hardcover book or notebook between their legs (spine up), as high as comfortable. Mark the top of the book on the wall and measure down to the floor.
Step 2: Use the youth bike size chart (20-26 inch wheels)
The ranges below are a starting point based on major retailer and brand guidance. Expect overlap and always double-check the specific brand’s chart.
| Size | Height | Inseam |
|---|---|---|
| XS | 148-160 cm | 68-74 cm |
| S | 160-170 cm | 72-78 cm |
| M | 170-180 cm | 76-84 cm |
| L | 180-188 cm | 82-90 cm |
| XL | 188-198 cm | 88-96 cm |
Useful minimums (sanity check): some guides list minimum height/inseam thresholds of about 120 cm for 20 inch, 127 cm for 24 inch, and 140 cm for 26 inch, with corresponding minimum inseams.
Step 3: Confirm fit (3 fast checks)
- Stand-over clearance: Your child should be able to stand over the top tube with feet on the ground and clearance between their body and the frame. Guidance ranges from about 1-2 inches to 2-4 inches depending on brand; more clearance helps beginners feel safe.
- Seat height: For balance or first pedal bikes, set the saddle so feet can be flat on the ground while seated. For more confident riders, toes touching can be enough.
- Reach and control: Even with the right wheel size, geometry differs. If possible, have your child sit on the bike to confirm comfortable reach to the bars.
What if your child is between sizes?
It’s tempting to size up, but oversizing can compromise stability and confidence. A practical rule: newer or cautious riders should choose the smaller size for easier handling; confident riders may manage the larger end of a range, but confirm stand-over and reach first.
FAQs
What size youth bike does my child need?
Most youth bikes fall into 20, 24, or 26 inch wheel sizes. Choose based on height and inseam, then confirm with stand-over clearance and reach.
Is age a reliable way to size a youth bike?
Age is a rough guide, but kids grow at different rates; height and inseam are more accurate.
How do I measure inseam for a youth bike?
Use the wall and book method: place a book between the legs (spine up), mark the top, then measure to the floor.
Should I buy a youth bike one size bigger so they can grow into it?
Usually no. Multiple guides warn that a bike that is too big can reduce confidence and safety versus a bike that fits now.
My child is between 24 and 26; which should I choose?
If they are newer or cautious, lean 24. If they are confident and meet stand-over and reach checks, 26 can work. Avoid sizing up if it compromises stability.
What’s the height range for a 20-inch youth bike?
Examples vary by brand. Some list about 115-130 cm; always confirm with the specific brand chart.
What’s the height range for a 24-inch youth bike?
Brand guidance commonly clusters around the mid-120s to mid-140s cm, with overlap depending on geometry.
What’s the height range for a 26-inch youth bike?
Many youth-specific 26 inch bikes target roughly 140-165 cm, with overlap depending on brand.
How much stand-over clearance should a youth bike have?
Guidance varies: some suggest about 1-2 inches, others 2-4 inches. More clearance generally helps beginners feel safer when starting and stopping.
How high should the seat be on a youth bike?
For early riders, set the saddle so feet can be flat on the ground; for more experienced riders, toes touching can be enough.
Do different brands fit differently even with the same wheel size?
Yes. Bikes with the same wheel size can vary between manufacturers, so always confirm with the brand chart and, ideally, a test sit or ride.
Does riding skill matter when choosing youth bike size?
It can. Less confident riders may struggle on the same bike a more skilled rider can handle, even within the same size band.