PLT to UCS Correlation Calculator

Simple calculator to convert axial point load strength index (Is(50)) results to uniaxial compressive strength (UCS) using a correlation factor.

What is the PLT to UCS Correlation Calculator?

This handy calculator takes your axial Point Load Test (PLT) results—often reported as Is(50)—and converts them into an estimated Uniaxial Compressive Strength (UCS). It uses a straightforward correlation factor to bridge the gap between quick field tests and traditional lab-based UCS measurements.

Why and When to Use It

PLT is a brilliant on-the-spot test for rock strength, particularly when you need a rapid check without hauling cores back to the lab for full UCS testing. The correlation gives you a ballpark UCS figure—ideal for early design decisions, ongoing site evaluations, or when you simply don't have enough time or budget for lab work. Our free tool does the maths for you, meaning you can pop in your Is(50) results and walk away with a concise UCS estimate in seconds, no complicated spreadsheets required.

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