Bicycle fit dimension worksheet
Record your inseam and your bike’s saddle, crank, handlebar and frame measurements, and compare your saddle height with two published rules. It is a worksheet, not a bike fit, and makes no health claims.
Inseam 400 to 1,100 mm, saddle height 300 to 1,200 mm, crank length 100 to 220 mm, rider height 1,000 to 2,500 mm, setback -200 to 400 mm, saddle to handlebar 200 to 1,200 mm, floor heights 300 to 1,600 mm, stack 300 to 900 mm and reach 250 to 600 mm, in mm, cm or inches. Calculated on your device; download a JSON report and a CSV of results. Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Bicycle fit dimension worksheet
- Choose the measurement unit and enter your inseam.
- Measure the saddle height from the bottom bracket centre to the saddle top, and enter the crank length.
- Add any optional measurements: setback, saddle to handlebar reach, floor heights and frame stack and reach.
- Review the ratios and differences from the reference heights, then download the JSON report or CSV.
Useful next steps
Two published saddle height rules
The LeMond rule sets saddle height, from the bottom bracket centre to the saddle top, at 0.883 × inseam. The Hamley and Thomas rule puts the saddle top 109% of inseam from the pedal axle with the crank in line with the seat tube, so the matching saddle height is 1.09 × inseam minus crank length. Both are described in Bini, Hume and Croft (Sports Medicine, 2011) and the 109% rule in Peveler and others (Journal of Strength and Conditioning Research, 2007), both checked 16 October 2026.
Reading the comparison
With an 820 mm inseam, a 725 mm saddle height and 172.5 mm cranks, the saddle is 0.94 mm above the LeMond reference and 3.7 mm above the Hamley and Thomas reference. Studies find that these rules give different heights and often disagree with knee angle methods, so the worksheet only records the numbers. It does not recommend a position or say anything about comfort, health or injury; a qualified bike fitter can assess fit.
Other measurements and limits
Drop is the saddle top height minus the handlebar top height, both measured from level floor. Stack divided by reach comes from the frame geometry chart. Inseam 400 to 1,100 mm, saddle height 300 to 1,200 mm and cranks 100 to 220 mm, in mm, cm or inches. Unit conversions use NIST SP 811 factors.