Giro
Register II MIPS
Everyday adult helmet with MIPS and a simple dial fit.
Universal Adult, 54–61 cm
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Bike size chart
Bike Size Chart: Find Your Frame Size
Compare road, mountain, gravel, hybrid, and kids bike sizes by height and inseam. Use the calculator when you want a size from your own measurements.
Need the step-by-step process? How to choose a bike size covers bike type, height, inseam, standover, and reach before you compare a chart.
All bike types
Road, mountain, gravel, hybrid, and kids charts in one place.
Cm & inches
Every chart shows both metric and imperial measurements.
Brand charts
Jump from this table to Trek, Giant, and Specialized.
Bike size charts by type
Each chart maps rider height and inseam to the recommended frame size. Use these as a starting range, then confirm with the calculator or a test ride.
Road bike size chart
Road bike frame sizes in cm. Use height and inseam to find your starting range.
Height
Height cm
Inseam
Frame Size
5'1"–5'4"
155–163
69–74 cm
48 cm (XS)
5'3"–5'6"
161–167
73–77 cm
50 cm (XS/S)
5'5"–5'7"
164–171
74–79 cm
52 cm (S)
5'7"–5'10"
169–178
77–82 cm
54 cm (M)
5'9"–6'0"
176–184
81–86 cm
56 cm (M/L)
5'11"–6'3"
181–190
85–90 cm
58 cm (L)
6'2"–6'6"
188–198
89–95 cm
61 cm (XL)
Height5'1"–5'4"
Height cm155–163
Inseam69–74 cm
Frame Size48 cm (XS)
Height5'3"–5'6"
Height cm161–167
Inseam73–77 cm
Frame Size50 cm (XS/S)
Height5'5"–5'7"
Height cm164–171
Inseam74–79 cm
Frame Size52 cm (S)
Height5'7"–5'10"
Height cm169–178
Inseam77–82 cm
Frame Size54 cm (M)
Height5'9"–6'0"
Height cm176–184
Inseam81–86 cm
Frame Size56 cm (M/L)
Height5'11"–6'3"
Height cm181–190
Inseam85–90 cm
Frame Size58 cm (L)
Height6'2"–6'6"
Height cm188–198
Inseam89–95 cm
Frame Size61 cm (XL)
Mountain bike size chart
Mountain bikes use letter sizes with typical traditional frame measurements. Wheel size is not a frame size.
Size
Height
Inseam
Traditional frame
XS
150–160 cm / 4'11"–5'3"
67–72 cm
13–14"
S
158–169 cm / 5'2"–5'7"
71–77 cm
15–16"
M
167–178 cm / 5'6"–5'10"
76–82 cm
17–18"
L
176–188 cm / 5'9"–6'2"
81–87 cm
19–20"
XL
186–198 cm / 6'1"–6'6"
86–93 cm
21–22"
XXL
193–204 cm / 6'4"–6'8"
91–98 cm
23"+
SizeXS
Height150–160 cm / 4'11"–5'3"
Inseam67–72 cm
Traditional frame13–14"
SizeS
Height158–169 cm / 5'2"–5'7"
Inseam71–77 cm
Traditional frame15–16"
SizeM
Height167–178 cm / 5'6"–5'10"
Inseam76–82 cm
Traditional frame17–18"
SizeL
Height176–188 cm / 5'9"–6'2"
Inseam81–87 cm
Traditional frame19–20"
SizeXL
Height186–198 cm / 6'1"–6'6"
Inseam86–93 cm
Traditional frame21–22"
SizeXXL
Height193–204 cm / 6'4"–6'8"
Inseam91–98 cm
Traditional frame23"+
Gravel bike size chart
Gravel sizing is close to endurance road sizing, but gravel bikes are usually more upright and need extra top-tube clearance. If two sizes fit, compare standover, stack and reach on the exact model. The smaller size generally provides a more compact fit and more clearance, while the larger size generally gives a longer cockpit. Choose based on the exact bike geometry rather than the size label alone.
Height
Height cm
Inseam
Frame Size
5'1"–5'5"
155–164
70–75 cm
XS (48–49 cm)
5'4"–5'8"
162–172
74–79 cm
S (50–52 cm)
5'7"–5'10"
170–179
78–83 cm
M (53–54 cm)
5'10"–6'2"
178–189
83–89 cm
L (57–58 cm)
6'1"–6'6"
186–197
87–94 cm
XL (60–61 cm)
Height5'1"–5'5"
Height cm155–164
Inseam70–75 cm
Frame SizeXS (48–49 cm)
Height5'4"–5'8"
Height cm162–172
Inseam74–79 cm
Frame SizeS (50–52 cm)
Height5'7"–5'10"
Height cm170–179
Inseam78–83 cm
Frame SizeM (53–54 cm)
Height5'10"–6'2"
Height cm178–189
Inseam83–89 cm
Frame SizeL (57–58 cm)
Height6'1"–6'6"
Height cm186–197
Inseam87–94 cm
Frame SizeXL (60–61 cm)
Hybrid & commuter bike size chart
Hybrid, city, and commuter bike sizes in inches and alpha labels. These bikes prioritize upright comfort and standover clearance.
Height
Height cm
Inseam
Frame Size
Notes
4'10"–5'2"
148–158
27"–29"
XS (13–14")
City/commuter entry size.
5'2"–5'6"
158–168
29"–31"
S (15–16")
Commuter sweet spot.
5'6"–5'10"
168–178
32"–34"
M (17–18")
Most common hybrid size.
5'10"–6'1"
178–185
33"–35"
L (19–20")
6'1"–6'4"
185–193
34"–36"
XL (21–22")
6'4"–6'6"
193–198
35"–36"
XXL (23–24")
Height4'10"–5'2"
Height cm148–158
Inseam27"–29"
Frame SizeXS (13–14")
NotesCity/commuter entry size.
Height5'2"–5'6"
Height cm158–168
Inseam29"–31"
Frame SizeS (15–16")
NotesCommuter sweet spot.
Height5'6"–5'10"
Height cm168–178
Inseam32"–34"
Frame SizeM (17–18")
NotesMost common hybrid size.
Height5'10"–6'1"
Height cm178–185
Inseam33"–35"
Frame SizeL (19–20")
Notes
Height6'1"–6'4"
Height cm185–193
Inseam34"–36"
Frame SizeXL (21–22")
Notes
Height6'4"–6'6"
Height cm193–198
Inseam35"–36"
Frame SizeXXL (23–24")
Notes
Starter kit
Helmet, light, lock, bottle, and a pant-leg strap. Size the bike here; buy the complete adult bike at a shop.
NiteRider
Swift 300
Compact USB headlight for commuting and dusk rides.
Handlebar mount, 300 lumens
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Kryptonite
Evolution Mini-7 with 4′ cable
Hardened U-lock plus a cable for wheels or a locked-together pair.
Fits most road, gravel, and hybrid frames
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CamelBak
Podium Chill 21 oz
Insulated squeeze bottle for everyday rides.
Fits a standard ~73 mm cage
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Green Guru
Narrow pant-leg strap
Upcycled inner-tube strap that keeps a pant leg off the chain.
Adjustable hook-and-loop, about 16 in long
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Kids bike wheel size chart
Kids bikes are sized by wheel diameter, not frame size.
Wheel
Height
Inseam
Typical age
12" wheel
90–105 cm / 2'11"–3'5"
35–42 cm
2–4 years
14" wheel
95–110 cm / 3'1"–3'7"
38–46 cm
3–5 years
16" wheel
100–115 cm / 3'3"–3'9"
42–52 cm
4–6 years
18" wheel
107–130 cm / 3'6"–4'3"
46–56 cm
5–7 years
20" wheel
115–135 cm / 3'9"–4'5"
50–60 cm
6–9 years
24" wheel
130–150 cm / 4'3"–4'11"
58–68 cm
8–12 years
26" wheel
145–160 cm / 4'9"–5'3"
66–74 cm
11+ years
Wheel12" wheel
Height90–105 cm / 2'11"–3'5"
Inseam35–42 cm
Typical age2–4 years
Wheel14" wheel
Height95–110 cm / 3'1"–3'7"
Inseam38–46 cm
Typical age3–5 years
Wheel16" wheel
Height100–115 cm / 3'3"–3'9"
Inseam42–52 cm
Typical age4–6 years
Wheel18" wheel
Height107–130 cm / 3'6"–4'3"
Inseam46–56 cm
Typical age5–7 years
Wheel20" wheel
Height115–135 cm / 3'9"–4'5"
Inseam50–60 cm
Typical age6–9 years
Wheel24" wheel
Height130–150 cm / 4'3"–4'11"
Inseam58–68 cm
Typical age8–12 years
Wheel26" wheel
Height145–160 cm / 4'9"–5'3"
Inseam66–74 cm
Typical age11+ years
Adult wheel size is not frame size
Adult bikes may use 26", 27.5", 29" or 700c wheels, but these numbers describe wheel diameter rather than frame size. A 17 or 19 inch figure on a mountain or hybrid frame is the other inch label: frame size, not wheel size.
Start with height. If two sizes overlap, use cycling inseam to choose.How to measure
Bike size calculator
Find a size from your measurements
Enter height and inseam, choose a bike type and brand, then come back to these tables.
Height and inseam for these charts
Use height and cycling inseam with the tables above. See How to measure for the method, then how to choose a bike size for standover, reach, and brand charts.
How to measure your height
Stand barefoot against a wall, heels touching. Place a book on your head, flat against the wall. Mark the wall at the bottom of the book. Measure from floor to mark in cm or inches.
How to measure your inseam
Stand barefoot with feet 6-8 inches apart. Place a book between your legs, spine up, pressed firmly against your crotch (simulating saddle pressure). Measure from the top of the book to the floor. This is your cycling inseam — not your pants inseam.
Standover clearance check
Your inseam should be at least 2-3cm (about 1 inch) greater than the bike's standover height for road bikes, and 5-7cm (2-3 inches) for mountain bikes. This ensures you can stand over the top tube with both feet flat.
Sizing tips
Charts give you a range. These tips narrow it down.
Between two sizes?
Go smaller for a sportier, more aggressive position. Go larger for a more upright, comfort-oriented ride. Your inseam and flexibility should drive the final decision.
Don't match by label alone
A 'Medium' in Trek is not the same as a 'Medium' in Giant or Specialized. Always match by the brand's published height range, not the size label.
Inseam beats height
Two riders of the same height can need different frame sizes if their inseams differ by more than 2 inches. Standover clearance is non-negotiable for safety.
Use the calculator for precision
The charts on this page give you a range. The calculator narrows it to one or two sizes by cross-referencing your height, inseam, bike type, and brand.
Want the full process instead of a lookup table? How to choose a bike size is the step-by-step guide; this page stays a chart.
Brand sizing comparison
At the same rider height, Trek, Giant, and Specialized labels differ. Match by height range, not by size label.
Height
Trek
Giant
Specialized
5'0"–5'3"
XS / 47
XS
49
5'3"–5'6"
S / 50
S
52
5'6"–5'9"
M / 54
M
54
5'9"–6'1"
ML / 56
M/L
56
6'1"–6'3"
L / 58
L
58
6'3"–6'6"
XL / 61
XL
61
Height5'0"–5'3"
TrekXS / 47
GiantXS
Specialized49
Height5'3"–5'6"
TrekS / 50
GiantS
Specialized52
Height5'6"–5'9"
TrekM / 54
GiantM
Specialized54
Height5'9"–6'1"
TrekML / 56
GiantM/L
Specialized56
Height6'1"–6'3"
TrekL / 58
GiantL
Specialized58
Height6'3"–6'6"
TrekXL / 61
GiantXL
Specialized61
Go deeper with brand-specific charts
Each brand page includes brand-specific sizing notes, model-level data, and a calculator link for that brand.
Questions
Bike sizing FAQ
Short answers for the most common bike sizing questions.
How do I use this bike size chart?
Pick the table for your bike type, match your height to a size range, then confirm with inseam. This page is a lookup chart. For the step-by-step process of how to choose a bike size, use the sizing guide.
What road bike size is 5'6" to 6'0" on this chart?
On the road chart above, 169–178 cm maps to 54 cm (M) and 176–184 cm maps to 56 cm (M/L). Confirm with inseam, then check the exact brand chart before buying.
Are bike sizes the same across brands?
No. Trek M (54cm) ≈ Giant M ≈ Specialized 54cm by height range, but the actual frame geometry differs. Trek offers an ML half-size that Giant and Specialized don't. Always match by the brand's published height range.
Should I use cm or inches for bike sizing?
Road bikes are typically sized in cm (frame size). Mountain and hybrid bikes are often sized in inches or alpha sizes (S/M/L). Kids bikes are sized by wheel diameter. Use the chart above for cross-reference.
What if my height and inseam suggest different sizes?
Trust your inseam for standover safety first. If your inseam is short for your height, go with the smaller frame. If your inseam is long, you have more flexibility — prioritize reach and stack for your riding style.
What does bicycle frame size inches mean?
On an adult mountain or hybrid frame, an inch label such as 17 or 19 is the traditional seat-tube measurement. It is a frame label, not a wheel diameter.
Are bike inches frame size or wheel size?
Both are possible. An adult mountain or hybrid inch label such as 17 or 19 describes the frame. Kids, BMX, and folding-bike inch labels such as 20 or 24 describe wheel diameter instead.
How do I use a bike size chart by height in inches?
Read your height off the Height column, then confirm the Inseam column. Every table above lists rider height in centimeters and in feet and inches, so a feet-and-inches measurement reads straight off the same row.
What mountain bike size in inches do I need?
Read the mountain table above: the letter label and the traditional inch label sit on the same row, and the Inseam column confirms the range. Then check standover and reach on the exact model, because the same inch label covers different geometry across brands.