Bike Frame Size Calculator
Find your bike frame size for road, mountain, gravel or hybrid bikes from your inseam — in centimetres and inches, with the typical S/M/L size.
How to use
- 1Measure your inseam: stand against a wall with a book pressed up between your legs, and measure from its top edge to the floor.
- 2Choose the bike type.
How it's calculated
Road/gravel: frame ≈ inseam (cm) × 0.665. Mountain: frame (inches) ≈ inseam (cm) × 0.226. Hybrid: ≈ inseam (cm) × 0.685. Always test ride — geometry varies by brand.
Frequently asked questions
Why use inseam instead of height?
Leg length determines standover height and saddle reach far better than overall height.
I'm between two sizes — which should I pick?
A smaller frame is usually more agile and easier to adjust up; a larger one more stretched and stable. Try both if you can.
Do brands size the same?
No — always check the manufacturer's own chart; this gives a starting point.