What frame size do I need? The most important question before every bike purchase — and the most common source of error. A frame that's too big or too small is nearly impossible to compensate for later. Get your answer here in 30 seconds: from height and inseam, directly for specific models from Canyon, Cube, Trek, Specialized, Giant, Scott and Rose.
Stand barefoot with your back against a wall, pull a book up firmly and horizontally into your crotch (simulating the saddle), and measure the distance from the top of the book to the floor. Measure twice and average. Inseam is a better predictor than height because it accounts for the leg-to-torso ratio.
| Bike type | Formula | Example (86 cm inseam) |
|---|---|---|
| Road bike | Inseam × 0.665 | ≈ 57 cm frame size |
| Gravel/cross | Inseam × 0.66 | ≈ 56–57 cm |
| Saddle height (LeMond) | Inseam × 0.883 | ≈ 75.9 cm (bottom bracket to saddle top) |
Watch out: manufacturers size their frames differently — a "56" from Trek isn't identical to a "56" from Cube, and Canyon uses its own labels (XS–XL). That's why the calculator above uses the manufacturers' own size charts directly.
The right frame is the prerequisite — but saddle height, saddle position (KOPS) and the cockpit make the riding position. That's exactly what our video analysis measures: knee angle, hip angle and KOPS in real centimetres, with concrete adjustment recommendations. So you'll also notice whether your current frame really fits — before knee pain tells you.
Check your riding position now for free by video →