Bike Saddle Height Calculator (LeMond and Hamley–Thomas Methods)
A starting saddle height for your bike from your inseam, by the LeMond and the Hamley–Thomas formulas, measured from the pedal axis and from the bottom bracket.
Results
What this tool does
Two simple rules give a first saddle height. Greg LeMond's multiplies your inseam by 0.883 and is measured from the centre of the bottom bracket along the seat tube to the top of the saddle. Hamley and Thomas, in a 1967 study, found 1.09 times the inseam measured from the pedal axle at its lowest point; subtract the crank length and it becomes the same kind of measurement, and the two methods usually land within a centimetre or two. Treat the result as a starting point and fine-tune by feel: with the pedal at the bottom of the stroke the knee should still be slightly bent, commonly about 25–35°, and the hips should not rock.
Formula
LeMond: 0.883 × inseam · Hamley and Thomas: 1.09 × inseam from the pedal axis, minus the crank length from the bottom bracket
Variables
| Symbol | Meaning | Unit |
|---|---|---|
ns | Inseam (crotch to floor, barefoot) | cm |
cr | Crank length | mm |
LM | Saddle height by LeMond (bottom bracket to top of saddle) | cm |
HT | Saddle height by Hamley and Thomas (bottom bracket to top of saddle) | cm |
HP | Pedal at the bottom to top of saddle (Hamley and Thomas) | cm |
DF | Difference between the two methods | cm |
Worked example
- Inseam (crotch to floor, barefoot)82 cm
- Crank length170 mm
- Saddle height by LeMond (bottom bracket to top of saddle)72.4 cm
- Saddle height by Hamley and Thomas (bottom bracket to top of saddle)72.4 cm
- Pedal at the bottom to top of saddle (Hamley and Thomas)89.4 cm
- Difference between the two methods0.0 cm
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.