Saddle height calculator
This saddle height calculator turns your inseam into the distance from the pedal axle to the top of the saddle. It uses sports science: the equation by Ferrer-Roca et al. (2012) and the classic rules of 106 % and 109 % of inseam. Enter the inseam in inches or centimeters.
How it is calculated
Saddle height is the distance from the centre of the pedal axle to the top of the saddle, measured with the pedal at its lowest point. It depends mainly on your inseam. From measurements of well-trained cyclists, Ferrer-Roca and colleagues (2012) derived the equation saddle height = 22.1 + 0.896 × inseam − 0.15 × knee angle (in cm and degrees, knee angle 30–40°); for the riders in the study this came to 108.6 to 110.4 % of inseam.
Three methods compared
| Inseam | 106 % | 109 % | Ferrer-Roca, 35° |
|---|---|---|---|
| 30 in | 31.8 in | 32.7 in | 33.5 in |
| 32 in | 33.9 in | 34.9 in | 35.3 in |
| 34 in | 36 in | 37.1 in | 37.1 in |
In centimeters: an 85 cm inseam gives 90.1 cm (106 %), 92.7 cm (109 %) and 93 cm (Ferrer-Roca, 35°). The classic rule is 109 % of inseam (after Hamley and Thomas), and a range of 106 to 109 % is often quoted; in the Ferrer-Roca study 56.5 % of riders were outside that range. Peveler and colleagues found that 109 % missed the recommended knee angle of 25 to 35° in 63 % (2007) and 73 % (2011) of cases. A review by Bini et al. (2011) calls the methods not well established and suggests setting the height by a knee angle of 25 to 30°.
How to measure
- Inseam: from the floor to the crotch (ischium), the length used in the studies.
- Saddle height: pedal at the bottom, from the centre of the pedal axle to the top of the saddle.
- Knee angle: 0° is a straight leg, measured with the pedal at its lowest point.
The right frame for your inseam is shown by the bike frame size calculator; gearing and cadence by the bike gear ratio calculator.
Frequently asked questions
What saddle height for a 32-inch inseam?
35.3 in with the Ferrer-Roca equation at a 35° knee angle, 34.9 in with the 109 % rule and 33.9 in with 106 % – measured from the pedal axle to the top of the saddle.
What is the 109 % formula?
Saddle height = inseam × 1.09. For an 80 cm inseam that is 87.2 cm.
Which knee angle is right?
Peveler recommends 25 to 35°, Bini et al. 25 to 30°. The Ferrer-Roca equation works with 30 to 40° measured while pedalling.
Why do the methods give different values?
The percentage rules depend only on the inseam; the Ferrer-Roca equation also on the knee angle. For short legs it lies above 109 %, for long legs below.
How do I measure my inseam?
From the floor to the crotch (ischium). This is how Peveler (2011) describes the measurement for the 109 % rule.
Does it work for road bikes and mountain bikes?
The equations come from studies with cyclists and are a starting value for any bike type. Then fine-tune in small steps by the knee angle.
Sources and legal basis
- Ferrer-Roca V, Roig A, Galilea P, García-López J. Influence of saddle height on lower limb kinematics in well-trained cyclists. J Strength Cond Res 2012;26(11):3025–9, abstract: recommended range 106–109 % of inseam; new equation gives 108.6–110.4 % of inseam (read 10.10.2026)
- Sensors 2021 (PMC7865533), Evaluation of Accelerometer-Derived Data … Saddle Height Changes in Triathlon, Eq. 1: SH = 22.1 + 0.896·E − 0.15·KA (cm, knee angle 30–40°); saddle height from centre of pedal axle to saddle top, pedal at the bottom (read 10.10.2026)
- Peveler WW et al. J Strength Cond Res 2007;21(4):1023–7 and Peveler & Green 2011;25(3):629–33, abstracts: 109 % of inseam (floor to ischium) vs. 25–35° knee angle; 109 % fell outside 25–35° in 63 % and 73 % of cases (read 10.10.2026)
- Bini R, Hume PA, Croft JL. Effects of bicycle saddle height on knee injury risk and cycling performance. Sports Med 2011;41(6):463–76, abstract: methods not well established; suggests knee flexion angle 25–30° (read 10.10.2026)
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