How to use the bike saddle height and bar drop calculator
Stand barefoot, pull a book up firmly into the crotch, measure from the floor to the top of the book and enter that inseam. The saddle height appears straight away. Switch the pedal type to cleats and a corrected figure appears as well, while a flat pedal leaves that row reading not applied. Enter both the saddle top height and the handlebar height measured from the ground and the drop between them is calculated too.
Saddle height is the inseam multiplied by 0.883, with the 0.885 variant from the same lineage shown alongside it. The reference line runs from the centre of the bottom bracket to the top of the saddle along the seat tube. The factor is generally attributed to the early 1980s coach Guimard and is often named after LeMond, though the attribution is disputed. Because the original formula assumed a flat pedal with a sole around 10 mm thick, cleats with a thin sole take 3 to 5 mm off (checked October 2026).
No formula for calculating bar drop from body measurements is included. No authoritative equation for it is published, and the calculated saddle height starts at the bottom bracket, so subtracting a ground-referenced bar height from it would be wrong. Drop here is only the difference between two heights you measured from the ground. The widely repeated 25 to 35 degree knee angle range appears only in secondary sources, so this page does not use it as a verdict. If something hurts or the numbers never feel right, a professional fit is the better route.
Frequently asked questions
From the centre of the bottom bracket to the top of the saddle, measured along the seat tube. The result uses the same reference, so measure the bike along that line too.
The calculated saddle height starts at the bottom bracket while bar height is normally measured from the ground, so the references differ. Drop is therefore only the difference between two heights you measured from the ground.
The original formula assumed a flat pedal with a sole around 10 mm thick. With cleats and a thin sole the foot sits closer to the axle, so a 3 to 5 mm deduction is commonly applied.