If you are between sizes, or comparing different brands, look at "Reach" and "Stack" on the bike's geometry chart.

Road bikes are typically sized in centimeters (cm). 4'11" – 5'2": 47 – 50 cm 5'3" – 5'6": 51 – 54 cm 5'7" – 5'9": 54 – 56 cm 5'10" – 6'0": 56 – 58 cm 6'1" – 6'3": 58 – 61 cm

The horizontal distance from the pedals (bottom bracket) to the handlebars. A longer reach feels more "stretched out" and aggressive.

The vertical height from the pedals to the handlebars. A higher stack puts you in a more upright, comfortable position. 4. Sizing for Kids

Mountain and hybrid bikes are typically sized in inches or categorical sizes (S, M, L). 5'0" – 5'4": 14 – 15 inches (Small) 5'5" – 5'8": 16 – 17 inches (Medium) 5'9" – 6'0": 18 – 19 inches (Large) 6'1" – 6'4": 20 – 21 inches (XL) 2. Measure Your Cycling Inseam

When standing over the bike's top tube with both feet flat, you should have at least 1 inch of clearance on a road bike and 2–3 inches on a mountain bike for safety. 3. Understanding Advanced Fit (Reach & Stack)

Height is the most common starting point for bike sizing. Use these general charts to find your baseline size.