Gradistat V 91 Free ((link))

GRADISTAT version 9.1 is a popular free software used for calculating grain size distribution and statistics from unconsolidated sediments.

The tool operates as a macro-enabled Microsoft Excel spreadsheet, making it highly accessible and easy to integrate into existing workflows. Key Features

Data Compatibility: Handles input from standard measuring techniques like sieving and laser granulometry.

Statistical Analysis: Automatically calculates critical sediment parameters, including mean, mode, sorting (standard deviation), skewness, and kurtosis. gradistat v 91 free

Physical Classifications: Classifies samples based on standard geological scales, such as the Folk and Ward method or the Wentworth scale.

Visual Output: Generates cumulative frequency curves and histograms to represent grain size distributions visually. Availability

You can download the software for free from the Kenneth Pye Associates Ltd (KPAL) website. It includes full instructions and is widely cited in geological and environmental research. GRADISTAT software - Kenneth Pye Associates Ltd GRADISTAT version 9

Disclaimer: GradiStat v9.1 is an older, freeware software package (often distributed via academic archives). This review reflects its functionality as a classic tool, not a modern cloud-based application.

5. Hydrometer Analysis Module

Unlike many basic tools, Gradistat v 9.1 includes the full hydrometer calculation with ambient temperature correction, meniscus correction, and zero correction.

Key Features

Data input: accepts multiple sample formats (single-column size classes, individual grain measurements, or cumulative percentages). Common supported units: phi scale and millimeters; conversion utilities typically included.
Statistical calculations:
- Central tendency metrics: arithmetic mean, geometric mean, median (D50).
- Dispersion metrics: standard deviation (folk & ward sorting), inclusive and moment measures.
- Shape metrics: skewness and kurtosis with different calculation conventions (moment vs. graphical).
Grain-size distribution analyses:
- Cumulative frequency curves (percent finer vs. size).
- Histogram and probability plot generation.
- Modal analysis: auto-identify unimodal vs. bimodal distributions and estimate mode positions.
Standard methods implemented: Folk & Ward (1957), Trask (1932), graphical methods (e.g., cumulative curves), and moment method. Options to switch between protocols or report multiple methods for comparison.
Export and reporting: export tables and plots to common formats (CSV, TXT, PNG) and generate printable summary reports.
Batch processing: apply analyses across multiple samples and compile comparative tables and plots.
Quality control: error checking for inconsistent input (non-monotonic cumulative percentages, negative sizes), and warnings for small sample sizes that can bias statistics.

Real-World Applications: Who Uses Gradistat v 9.1?

MSc/PhD Students: Analyzing sediment cores for paleoenvironmental reconstruction.
Coastal Engineers: Classifying beach nourishment sand – must meet mean grain size and sorting specifications.
Oil & Gas Geologists: Describing reservoir heterogeneity in sandstones.
Archaeologists: Distinguishing natural soil from anthropic sediments (e.g., middens).
Teaching Labs: Universally used in undergraduate sedimentology courses because it is free and transparent.

Step 3: Enter Your Data

Go to the Input sheet.
Paste your sieve intervals (starting with the largest mesh) and corresponding weights.
Ensure total dry weight is correct at the bottom.

Compatibility and Integration

Commonly pairs with GIS and sedimentological workflows: export CSVs for geospatial plotting, link sample metadata (location, depth) to analyses.
Works as a standalone application in many releases; check file format compatibility with other grain-size tools (e.g., GRADISTAT earlier versions, Pebble Count tools).

How to Get Gradistat v 9.1 Free (Legally)

A common point of confusion: Is Gradistat v 9.1 really free? And where can you download it safely today? Key Features

Official Status: The original website (www.kpal.co.uk) no longer hosts the software. The developers have retired or moved on. However, the software was released as freeware for academic and non-commercial use. No one currently holds exclusive distribution rights, but the original license remains in force.

Safe Download Sources (as of 2025-2026):

GitHub: Several geoscience repositories mirror Gradistat v 9.1 (e.g., sedipt, geostats). Look for a .xls (not .xlsx) file, as macros require the old format.
University Websites: Many geology departments (e.g., University of Oregon, University of Texas, University of Brighton) host local copies of Gradistat 9.1 for student use. Search site:edu "gradistat 9.1"
ResearchGate / Academia.edu: Numerous researchers have uploaded the original .xls file as a supplementary resource.
Wayback Machine (Internet Archive): The original download page from the Kenneth Pye Associates site can often be retrieved.

⚠️ Important Warning: Never download Gradistat from untrusted "crack" or "serial key" websites. The software is free – anyone charging for it is scamming you. Always scan downloaded .exe or .xls files for malware (though the original is a simple macro workbook).

Comparison to Modern Free Alternatives