QO Crank Length Calculator

Find your perfect crank length.

The right crank length can transform how you ride, improving comfort, efficiency, and even power output.

Our calculator helps you find your optimal fit based on your inseam measurement, combining the latest biomechanical research with real-world experience from professional riders.

Why it matters

Crank length influences your entire pedaling dynamic, from joint angles to power transfer.

Shorter cranks tend to open the hip angle, reduce knee stress, and allow a smoother, more aerodynamic position, especially on modern performance bikes.

Longer cranks may increase leverage but often bring diminishing returns in power and comfort.

Recent studies and pro trends show many riders moving toward 165 mm or even shorter setups, optimizing efficiency without sacrificing watts.

Ultimately, the goal is to find the sweet spot where biomechanics, comfort, and performance align.

How to use it

  1. Measure your inseam (in centimeters).
  2. Move the slider to match your measurement.
  3. Instantly get your recommended crank length.

You will also receive your personalized result and our Crank Length Guide by email.

Enter your inseam measurement and get your guide by email

We'll send you your personalized crank length guide

Measurement protocol

How to measure your inseam

Your inseam is the foundation of the calculation. One book, one wall, ninety seconds — measured like in a bike fit lab.

  1. Stand against a wall

    Barefoot, feet about 15 cm apart, with your back and heels touching the wall.

  2. Raise a book between your legs

    Slide it up, spine horizontal, until it presses firmly against your pubic bone — exactly like a saddle would.

  3. Measure down to the floor

    Keep the book level and measure from its top edge straight down to the floor, in centimeters.

Repeat the measurement three times and use the average — accuracy here means precision in your crank length.