What size bike do I need for my height?

Bike size depends on both height and inseam. For road bikes: 5'0"-5'3" typically fits 48-50 cm, 5'3"-5'6" fits 51-53 cm, 5'6"-5'9" fits 54-55 cm, 5'9"-6'0" fits 56-58 cm, and 6'0"-6'3" fits 58-61 cm. Use our calculator with your inseam measurement for the most accurate result.

How do I measure my inseam for bike sizing?

Stand barefoot against a wall with feet shoulder-width apart. Place a hardcover book between your legs snug against your crotch, spine facing up. Have someone measure from the top of the book straight down to the floor. This measurement in centimeters is your cycling inseam.

What if I'm between two bike frame sizes?

If you're between sizes, choose the smaller frame if you prefer a sportier, more aggressive position, or the larger frame if you want a more upright, comfort-oriented ride. Shorter torso and arms also favor the smaller size, while longer torso and arms favor the larger.

Is bike frame size measured differently for road and mountain bikes?

Yes. Road bike frames are measured in centimeters along the seat tube and run larger (typically 48-62 cm). Mountain bike frames use S/M/L sizing and have shorter seat tubes for more standover clearance. A rider on a 56 cm road bike might ride a Medium or Large mountain bike.

What is standover height and why does it matter?

Standover height is the distance from the ground to the top tube when straddling the bike. You need at least 2-5 cm of clearance for road bikes and 5-10 cm for mountain bikes. Insufficient standover clearance is a safety issue when stopping quickly.

How do I know if a bike is too big or too small?

A bike is too big if you can't comfortably straddle the top tube, your arms are fully extended to reach the bars, or you can't reach the ground with your toes while seated. A bike is too small if you feel cramped, your knees hit the handlebars, or your back is excessively hunched.

Does stem length affect bike fit?

Yes, stem length fine-tunes your reach to the handlebars. A standard stem is 90-110 mm for road bikes. If you need a stem shorter than 80 mm or longer than 130 mm to feel comfortable, the frame is likely the wrong size. Stems between 90-110 mm give the best handling.

Should I size up or down for a gravel bike?

For gravel bikes, many riders size down for better off-road handling and maneuverability. A slightly smaller frame gives more standover clearance on rough terrain and lets you move the bike around more easily. However, if you prioritize long-distance comfort, your standard road size works too.

Quick Answer: Frame size (cm) = inseam (cm) x 0.70 for road bikes, x 0.66 for mountain bikes. A 84 cm inseam = 56 cm road frame.

Bike Frame Size Calculator

Find the perfect bike frame size for your body. Enter your height and inseam to get frame size recommendations for road, mountain, hybrid, and gravel bikes — plus standover height and stem length suggestions.

Cyclist being fitted for the correct bike frame size

54 cm

Most Common Road Size

Medium

Most Sold MTB Size

2-5 cm

Road Standover Clearance

90-110 mm

Standard Stem Length

Calculate Your Bike Frame Size

Your Height

Feet

Inches

Your Inseam (Cycling Inseam)

Enter inseam in inches (e.g. 33)

Bike Type

Road Bike Size Chart

Use this road bike size chart as a general guide. Inseam-based calculations (above) are more accurate than height alone.

Rider Height	Rider Height (cm)	Frame Size (cm)	Size Label
4'10" - 5'1"	147 - 155 cm	47 - 49 cm	XXS
5'1" - 5'3"	155 - 160 cm	49 - 51 cm	XS
5'3" - 5'6"	160 - 168 cm	51 - 53 cm	S
5'6" - 5'9"	168 - 175 cm	54 - 55 cm	M
5'9" - 6'0"	175 - 183 cm	56 - 58 cm	M/L
6'0" - 6'3"	183 - 191 cm	58 - 61 cm	L
6'3" - 6'6"	191 - 198 cm	61 - 63 cm	XL
6'6"+	198+ cm	63+ cm	XXL

Mountain Bike Size Chart

Mountain bikes use S/M/L sizing. Frame sizes are smaller than road bikes because MTB geometry prioritizes standover clearance and maneuverability.

Rider Height	Rider Height (cm)	Frame Size (cm)	Frame Size (in)	Size Label
4'10" - 5'3"	148 - 160 cm	33 - 37 cm	13" - 14"	XS
5'3" - 5'7"	160 - 170 cm	38 - 42 cm	15" - 16"	S
5'7" - 5'11"	170 - 180 cm	43 - 47 cm	17" - 18"	M
5'11" - 6'2"	180 - 188 cm	48 - 52 cm	19" - 20"	L
6'2" - 6'6"	188 - 198 cm	53 - 57 cm	21" - 22"	XL
6'6"+	198+ cm	58+ cm	23"+	XXL

How to Measure Your Inseam for Bike Sizing

Your cycling inseam is the single most important measurement for bike sizing. Here is how to measure it accurately in five steps.

1

Stand barefoot against a wall

Remove your shoes and socks. Stand with your back flat against a wall, feet shoulder-width apart on a hard floor (not carpet).
2

Place a book between your legs

Take a hardcover book and place it between your legs, spine facing up, pulled snugly into your crotch. This simulates sitting on a bike saddle.
3

Keep the book level

Make sure the book is perfectly horizontal and pressed firmly upward. It helps to have someone assist you from the side.
4

Mark and measure

Have a helper mark the wall at the top edge of the book. Then measure from the floor straight up to the mark with a tape measure. This distance is your cycling inseam.
5

Measure twice

Repeat the process two or three times and take the average. Small variations are normal; consistency matters. Record in both centimeters and inches for reference.

Tip: Your cycling inseam is typically 1-2 cm shorter than your pants inseam because the book simulates saddle pressure more accurately than trouser measurements.

What If I'm Between Sizes?

It is common to fall between two frame sizes. Here is how to decide which way to go:

Choose the Smaller Frame If You:

▼ Prefer a sportier, more aggressive riding position
▼ Have a shorter torso relative to your legs
▼ Prioritize nimble handling and quick steering
▼ Plan to ride off-road or gravel (more clearance)
▼ Are still growing or want room for a longer stem later

Choose the Larger Frame If You:

▲ Prefer a more upright, comfort-oriented position
▲ Have a longer torso relative to your legs
▲ Prioritize stability at higher speeds
▲ Ride primarily on paved roads and long distances
▲ Have longer arms and prefer a stretched-out reach

Pro Tip: When in doubt, size down. It is easier to make a small frame fit with a longer stem and raised seatpost than to make a too-large frame feel comfortable. A stem change of 10-20 mm is normal; needing more than 30 mm usually means the frame is the wrong size.