Climbing Finger Strength Ratio Calculator

How Climbing Finger Strength Ratio Is Calculated

Finger strength is the single strongest predictor of climbing performance. The standard measure is the maximum weight you can hang from a 20mm edge for 7-10 seconds using a half-crimp grip, expressed as a ratio of your body weight.

The Strength Ratio Formula

Strength Ratio = (Body_Weight + Added_Weight) / Body_Weight

If you cannot hang body weight, the added weight is negative (you used a pulley to remove weight):

Strength Ratio = (Body_Weight - Assistance_Weight) / Body_Weight

Benchmark Table by Climbing Grade

These benchmarks are based on data collected from hundreds of climbers by researchers including Eva Lopez and Lattice Training:

Worked Example

A 70 kg climber who can hang from a 20mm edge with 15 kg added:

• Strength Ratio = (70 + 15) / 70 = 1.21
• This corresponds roughly to a 7a (V6) climber
• To progress to 7b (V8), they need a ratio of ~1.30
• Target added weight: 1.30 × 70 - 70 = 21 kg

Edge Depth Conversion

If you test on a different edge depth, approximate conversions:

• 18mm results are roughly 5% lower than 20mm
• 15mm results are roughly 15% lower than 20mm
• 10mm results are roughly 30% lower than 20mm

Training Progression

A realistic improvement rate for finger strength is 5-10% per training cycle (6-8 weeks). Attempting faster gains significantly increases the risk of pulley injuries. Always warm up thoroughly before maximal hangs and never train finger strength on consecutive days.