Use this geological calculation for a transparent first-pass interpretation of measured rock, soil, fluid, well, stratigraphic, isotopic, geophysical, or seismic data under an explicitly selected model.

Run length (cm)

Total core run length in centimetres.

Pieces

Recovered piece lengths in centimetres; pieces of 10 cm or more count as sound.

Rock Quality Designation RQD = 100 * (sum of intact core pieces at least 10 cm long) / total drilled core run length. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Intact length (cm)

Sum of sound piece lengths in centimetres.

RQD (%)

Rock Quality Designation as a percentage.

• Geotechnical correlations and idealized failure models depend on stratigraphy, sampling disturbance, drainage, stress history, groundwater, density, anisotropy, scale, construction sequence, and laboratory or field method. Site-specific design requires investigation and code factors.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Compare independent measurements and models, retain units and analytical metadata, propagate uncertainty, and validate interpretations against logs, cores, maps, laboratory data, or field observations.

• Q System Rating Calculator

  NGI rock mass quality Q = (RQD/Jn) * (Jr/Ja) * (Jw/SRF) from the six Barton parameters supplied directly.

• Rock Mass Rating RMR Calculator

  Bieniawski RMR total from the five sub-ratings (strength max 15, RQD max 20, spacing max 20, groundwater max 15, joint condition max 30) with the standard RMR class boundaries.

• Rate Of Penetration Calculator

  Compute drilling rate of penetration in metres per hour from drilled length and elapsed time.