Los Angeles Abrasion Value Calculator
Percent loss (LA abrasion value) of a coarse aggregate sample from its mass before and after the Los Angeles abrasion test.
Result appears here
Fill in the fields and press Calculate.
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).
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.
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