Bike Frame Size Calculator
Calculate a practical bike frame size from height and inseam, then translate the result across road, gravel, mountain, and hybrid sizing labels.
Height
Find the first frame range
Inseam
Check standover clearance
Bike type
Translate cm, inches, or S/M/L labels
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.
Frame labels
Frame size changes by bike type.
A road frame may be listed as 54 cm, a hybrid as 18 in, and a mountain bike as medium. Use the calculator result as a shortlist, then check the brand's exact geometry.
Frame size FAQ
Frame size is a label. Standover, stack, and reach explain how that label will feel.
How do I calculate bike frame size?
Use height to find the first size range, then use inseam to check standover. Road frames are often labeled in centimeters, mountain and hybrid frames may use inches or S/M/L labels.
Is frame size the same as bike size?
Frame size is one part of bike size. The same frame label can fit differently because stack, reach, standover, wheel size, and cockpit setup vary by bike type and brand.
Should I use inches or centimeters for frame size?
Use the unit the brand publishes. Road bikes commonly use centimeters, hybrid and mountain bikes often use inches or alpha labels, and kids bikes usually use wheel size.