Find your ideal frame geometry using body measurements or fine-tune from your current bike. Reach and stack are the most reliable way to compare frames across brands and sizes.
Reach and stack are the two most important measurements for comparing bike frame geometries. Reach is the horizontal distance from the bottom bracket center to the top of the head tube, and stack is the vertical distance between those same two points.
Unlike traditional sizing labels (S, M, L) or seat tube length, reach and stack give you a standardized way to compare frames from any manufacturer. Two bikes labeled "54cm" can have very different reach and stack values, resulting in completely different riding positions.
Lower stack, longer reach for aerodynamics.
Balanced geometry for versatile riding.
Higher stack, shorter reach for comfort.
| Frame Size | Typical Reach (mm) | Typical Stack (mm) | Rider Height |
|---|---|---|---|
| 48cm (XS) | 365–375 | 495–515 | 155–165 cm / 5'1"–5'5" |
| 51cm (S) | 373–383 | 515–535 | 165–172 cm / 5'5"–5'8" |
| 54cm (M) | 381–391 | 535–555 | 172–178 cm / 5'8"–5'10" |
| 56cm (M/L) | 387–397 | 555–575 | 178–183 cm / 5'10"–6'0" |
| 58cm (L) | 393–403 | 575–595 | 183–190 cm / 6'0"–6'3" |
| 61cm (XL) | 400–410 | 595–615 | 190+ cm / 6'3"+ |
While this calculator provides a solid starting point, a professional bike fit takes into account your flexibility, injury history, pedaling dynamics, and long-term goals. If you experience persistent discomfort or are investing in a new frame, a professional fitting session is highly recommended.
Many bike fitters use reach and stack as the foundation of their sizing process. Bringing your calculated values to a fitting session gives your fitter a head start and helps ensure you end up on the best frame for your body.
Fine-tune your reach with the right stem length
Get your overall road bike frame size recommendation
Complete your cockpit fit with proper bar width
Optimize your saddle position for power and comfort
Universal sizing tool for all bike types
TT and triathlon sizing with stack & reach targets
Measure from the top of your sternum (sternal notch) to your crotch
Measure from the acromion (shoulder bone) to the center of your wrist
Measure from the ground to your crotch while standing against a wall
Enter your body measurements to find your ideal reach and stack range