Los Angeles Abrasion Value Calculator
LA abrasion loss = (original sample mass − mass retained on the 1.70 mm No. 12 sieve after the test) ÷ original mass × 100. A standard Grading B charge of 5,000 g with 3,650 g retained gives a 27.0% loss; lower is tougher. It reports the raw result, not a pass or fail. Related: Aggregate Specific Gravity Calculator.
How it's calculated: Loss (%) = (original mass − mass retained on the No. 12 sieve after the test) ÷ original mass × 100.
Result appears here
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Formula, calculation, assumptions and sources
LA abrasion loss (%) = (Original mass − Mass retained on No. 12 sieve after test) ÷ Original mass × 100
Run the calculation to see each step with your own numbers.
A standard Grading B (5,000 g) sample, 3,650 g retained on the No. 12 sieve after 500 revolutions.
Loss = (5,000 − 3,650) ÷ 5,000 × 100 = 27.0%
- Standard Grading B charge (5,000 g, 11 spheres, 500 revolutions) is the default — other ASTM C131 gradings (A, C, D) use a different charge mass and sphere count; enter your test's actual original mass regardless.
- The result is the raw abrasion loss percentage only — it does not apply an acceptance/rejection threshold, which depends on the aggregate's intended use and the specifying agency (commonly a maximum of 40–50% for base course, lower for surface course or concrete aggregate).
- Assumes the test was run per ASTM C131 (aggregate ≤ 37.5 mm) or ASTM C535 (aggregate > 19 mm) procedure; the math is identical either way.
- What counts as a 'good' LA abrasion result?
- Lower is better (less material degraded). Many state DOT base-course specs cap it around 40–50% maximum loss; surface-course and PCC aggregate specs are often stricter (30–45%). Check the spec for your specific application — this calculator gives the raw test result, not a pass/fail.
- Which grading (A/B/C/D) should I use?
- It depends on your aggregate's particle-size range — ASTM C131 Table 1 sets the charge (original mass and number of steel spheres) for each grading based on the size distribution of your sample. Enter your test's actual original mass either way; the loss formula is the same for every grading.
- Is this the same as the Aggregate Crushing Value or Aggregate Impact Value test?
- No — those are separate British/Indian Standard (BS 812 / IS 2386) methods with their own procedures and no direct ASTM equivalent. The LA abrasion test (ASTM C131/AASHTO T96) is the standard US/AASHTO test for the same general property (aggregate toughness).
- How do you calculate the LA abrasion value?
- Subtract the mass retained on the 1.70 mm (No. 12) sieve after the test from the original mass, divide by the original mass and multiply by 100. 5,000 g with 3,650 g retained gives 1,350 ÷ 5,000 × 100 = 27.0%.
- What sample mass does Grading B use?
- 5,000 g, tested with 11 steel spheres for 500 revolutions, per the ASTM C131 note on this page. Other gradings use a different charge, so enter your test's actual original mass.
Test method & formula
ASTM C131/C131M, 'Standard Test Method for Resistance to Degradation of Small-Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine'; ASTM C535 for larger-size aggregate; AASHTO T96 is the equivalent AASHTO standard.
About the Los Angeles Abrasion Value Calculator
The Los Angeles Abrasion Value Calculator turns the before-and-after masses from an LA abrasion machine test into the percent loss that quantifies a coarse aggregate's resistance to degradation by abrasion and impact — the standard test for judging whether an aggregate is tough enough for a base course, surface course or concrete. Enter the original sample mass and the mass retained on the 1.70 mm (No. 12) sieve after the machine run.
What you enter
- Original sample mass — Standard Grading B charge is 5,000 g with 11 steel spheres, 500 revolutions (ASTM C131).
- Mass retained on 1.70 mm (No. 12) sieve after test
What you get back
- LA abrasion loss — %. Lower is tougher (more resistant to abrasion).
The formula, a worked example, the assumptions behind it and the sources are shown in full below the calculator.
Related calculators
- Sieve Analysis & Gradation Calculator — Percent passing at each standard sieve and the fineness modulus, for an aggregate or soil sample, from the weight retained on each sieve.
- Aggregate Specific Gravity & Water Absorption Calculator — Bulk (oven-dry and SSD), apparent specific gravity and water absorption of a coarse aggregate sample from its oven-dry, SSD and submerged mass.
- Gravel Calculator — Gravel by volume and by delivered weight for driveways, paths and fill.
Related articles
- What Does the Los Angeles Abrasion Test Measure? — The LA abrasion test simulates the wear and impact aggregate experiences in service, reporting how much of the material breaks down as a percentage.
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