Cam Sizing Calculator
Find the right cam size for a given crack width. Enter the crack measurement and get recommended cam sizes with expansion range and placement quality rating.
Inputs
Results
Best Cam Size
#1
Expansion Percentage
79%
How to Use This Calculator
- Measure the crack width at its narrowest point in millimeters using a ruler or finger span.
- Enter the crack width — the calculator finds cams whose expansion range covers that measurement.
- Read the Recommended Cam Size (e.g., Black Diamond #2 or Camalot C4 #1) for common cam ranges.
- Check Expansion Percentage to confirm the cam is placed in its optimal mid-range (not over- or under-cammed).
- Review Placement Quality (out of 10) — higher scores mean a more secure, bomber placement.
- Use the output to build your rack: carry at least one cam per crack size in the route's crux sections.
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