How to Measure the Inseam for Cycling

Bikes come in a variety of frame sizes. To determine what frame size you need, measure your inseam. You can then enter this measurement into a formula or go to a bicycle shop with the measurement to calculate the proper frame size. However, this is just a starting point. The Colorado Cyclist website notes that these formulas may result in a bike that is too small for taller riders. Once you calculate your bike frame size using your inseam, try out bikes with frames a few sizes up and a few sizes down to find the perfect fit.

Things You'll Need

  • Book
  • Measuring tape
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Instructions

    • 1

      Take your shoes off. Stand with your heels and back against a wall. Set your feet 6 to 8 inches apart.

    • 2

      Place a book between your legs with the spine of the book facing up and one edge against the wall. Keep the book perpendicular to the floor and slide it up firmly into your crotch. The spine of the book simulates the feel of the bike seat. Press the book up high enough to replicate the pressure you feel when sitting on a bike.

    • 3

      Have a friend measure from the spine of the book to the floor. Take the measurement in centimeters. If centimeters are not available, measure in inches and multiply by 2.54 to convert inches to centimeters.

    • 4

      Repeat the above process three times. Add the three measurements together and divide the total by three to calculate the average. Use this average as your inseam length.