Reach & Stack Calculator

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. For the rest of your contact-point setup, follow our complete bike fitting guide.

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.