How do I measure my inseam?

Stand barefoot with your back against a wall, feet 15cm apart. Place a book between your legs, spine up, and press firmly into your crotch. Measure from the top of the book to the floor. This is your cycling inseam — it is more accurate than trouser inseam for bike fitting.

What if I am between frame sizes?

If between sizes, go smaller for a sportier, more aggressive position (better for racing and gravel), or larger for a more upright, comfortable position (better for touring and bikepacking). A slightly small frame with a longer stem is generally more comfortable than an oversized frame.

Does frame sizing differ between bike types?

Yes, significantly. Mountain bike frames are measured differently and are smaller than road/touring frames. A rider who uses a 56cm road frame might use a 48cm or Large mountain bike frame. Gravel bikes fall between road and mountain sizing. Always use the correct formula for your bike type.

How important is frame size for bikepacking?

Getting the right frame size is crucial for bikepacking comfort over long distances. A frame that is too large causes back pain and neck strain. A frame that is too small feels cramped and limits pedalling efficiency. For multi-day trips, prioritise comfort over aggressive positioning.

CampCalcs

Frame Size Calculator

Calculate the right bike frame size based on your height and inseam measurement.

Your Height

Inseam Length

Bike Type

How We Calculate This

Frame Size Calculation

Frame size = Inseam x Factor

Road: 0.665, Touring: 0.66, Gravel: 0.64, Mountain: 0.59

Standover Height

Standover clearance = Inseam x 0.88

You need at least 2-5cm of clearance over the top tube when standing flat-footed.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.