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Sieve Analysis and Grain Size Distribution Calculator

Sieve analysis describes the particle-size distribution, or gradation, of a granular soil or aggregate from the mass passing or retained by progressively smaller openings. GeoMiner accepts either cumulative percent-passing pairs or retained-mass pairs. Every row contains a positive sieve opening in millimetres and one measured value. Rows can be pasted from a spreadsheet with comma, tab, semicolon, or space separators, and their order does not matter because the calculator sorts the data by opening. It rejects duplicate openings, non-finite numbers, percentages outside zero through 100, negative mass, and a percent-passing curve that decreases as opening size increases. In mass-retained mode, every retained value and the separate pan mass must use one consistent unit. The particular mass unit cancels from the percentage calculation. Total entered sample mass is the sum of mass retained on every listed sieve plus pan mass. Cumulative retained mass is summed from the largest opening downward. Cumulative percent passing equals 100 multiplied by one minus cumulative retained mass divided by total entered mass. This arithmetic assumes every retained value and the pan belong to the same tested sample and mass basis. A missing fraction, transcription error, wet-versus-dry mismatch, loss during washing or transfer, or inconsistent unit invalidates the resulting curve even if software can still produce numbers. The grain-size distribution chart plots cumulative percent passing on a linear vertical axis and particle size in millimetres on a logarithmic horizontal axis. This semi-log convention spreads several orders of magnitude of particle size so the measured curve can be inspected and characteristic sizes can be read. D10 is the particle size at which 10 percent of the tested mass is finer or passing, D30 corresponds to 30 percent passing, and D60 corresponds to 60 percent passing. The U.S. Army Corps of Engineers describes D10 as effective size and publishes these D-value definitions for grain-size curves. When an entered point exactly matches a target percentage, GeoMiner uses that opening. Otherwise it finds adjacent points whose cumulative passing values bound the target and interpolates straight between their logarithmic particle sizes. The implemented equation is log10 Dx equals log10 Da plus the fraction x minus Pa divided by Pb minus Pa , multiplied by log1

Verification resources

Cross-check terminology, classification, methods, and safety with these authoritative external resources.

  • undefined. Defines D10, D30, D60, percent fines, Cu and Cc, explains well- versus poorly graded coarse soils, and states that both coefficient criteria are required for the corresponding USCS gradation descriptor.
  • undefined. Describes grain-size analysis by sieving and sedimentation, defines D10, D30 and D60, and publishes the coefficient-of-uniformity and coefficient-of-curvature equations.
  • undefined. Publishes cumulative percent-passing sieve data, grain-size curves, D-values, Cu and Cc for tested backfills; GeoMiner uses one published dataset as its worked example.
  • undefined. Defines percent passing on an oven-dry weight basis and lists nominal No. 4 and No. 200 sieve openings used for bounded gravel, sand and fines arithmetic.

Read GeoMiner's editorial methodology.

Common questions

How are D10, D30 and D60 calculated?
Each Dx is the particle size at which x percent of the tested mass is finer or passing. GeoMiner interpolates particle size between adjacent entered curve points on the logarithmic size axis and does not extrapolate beyond the measured curve.
What are Cu and Cc?
The coefficient of uniformity is Cu = D60 / D10. The coefficient of curvature is Cc = D30 squared / (D10 x D60). Both require a curve that bounds D10, D30 and D60.
Can I enter mass retained instead of percent passing?
Yes. Enter each sieve opening and retained mass plus any pan mass. All masses must use one unit. The calculator converts the mass balance to cumulative percent passing before plotting.
Does this calculator assign a complete USCS soil symbol?
No. It can compare Cu and Cc with selected sand or gravel coefficient thresholds, but complete classification can also require percent fines, Atterberg limits, organic characteristics, particle-size boundaries, and the governing method.
Why is a D-value unavailable?
A D-value is unavailable when the entered cumulative curve does not extend below and above its target percentage. Add measured bounding data; GeoMiner intentionally does not extrapolate.
Is percent passing the same as percent retained?
No. Percent passing is the cumulative fraction finer than a sieve opening. Percent retained describes material held on a sieve, while cumulative retained includes that sieve and every coarser sieve.

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