How to Read a Sieve Analysis
From retained weights to percent passing, the gradation curve, D-values and the fineness modulus
How to read a sieve analysis: the short version
A sieve analysis report lists how much of a dried sample stayed on each sieve. Reading it means converting those masses into percent passing at each sieve, then comparing that column with what the job requires: a specification band, a fineness-modulus range or a soil-classification rule.
- Check the masses: what the sieves and pan hold should match the mass that went on them.
- Read the percent-passing column from the largest sieve to the smallest.
- Compare every sieve with the specification band for the material.
- For concrete sand, check the fineness modulus.
- For soil classification or drainage work, read D10, D30 and D60 and work out Cu and Cc.
What the test measures
A sieve analysis (commonly run to a standard such as ASTM C136 for aggregates) shakes a weighed sample through a stack of sieves with progressively smaller openings, then weighs how much material is retained on each sieve. This shows the particle-size distribution — how much of the sample is coarse versus fine. How the test is run, and where it is used, is covered in Sieve Analysis Explained; this guide is about reading the results.
From retained weight to percent passing
For each sieve, cumulative retained weight (the running total retained on that sieve and all coarser sieves above it) is divided by the total sample weight and expressed as a percentage. Percent passing is 100% minus cumulative percent retained — it tells you what fraction of the sample is finer than that sieve's opening size.
For example, in a 500 g sample with 200 g retained on the sieves above and 120 g on this sieve, the cumulative retained is 320 g, or 64%, so 36% passes this sieve. The Sieve Analysis Calculator runs the same arithmetic for a whole stack.
Check the masses first
Under ASTM C136, the total mass after sieving should agree with the mass placed on the sieves within 0.3%; if it doesn't, the result shouldn't be used for acceptance. A bigger gap usually means spillage, material stuck in the mesh or a weighing error. Percentages are worked out on the original dry mass, including any fines removed by washing over the No. 200 sieve first (ASTM C117).
What each column in the report means
| Column | What it tells you | How it is calculated |
|---|---|---|
| Mass retained | Material caught on that sieve only | Weighed directly |
| Individual % retained | Share of the sample between this sieve and the next larger one | Mass retained ÷ original dry mass × 100 |
| Cumulative % retained | Share coarser than this sieve | Running total of mass retained ÷ original dry mass × 100 |
| % passing | Share finer than this sieve | 100 − cumulative % retained |
Reading the gradation curve
A gradation curve plots percent passing on the vertical axis against sieve size on a logarithmic horizontal axis, so each standard sieve sits roughly the same distance from the next. The shape of the curve is the quickest way to see what kind of material you have.
- A smooth, gently sloping S-shape that spans many sieves: well graded, with sizes that fill each other's voids.
- A steep, nearly vertical curve: uniformly graded, with most particles close to one size.
- A flat step across one or more sieves: gap graded, with some sizes missing.
- A curve that reaches almost zero well above the No. 200 sieve: open graded, with very few fines.
Maximum size and nominal maximum size
In specification terms, the maximum size is the smallest sieve opening the whole sample is required to pass, and the nominal maximum size is the smallest opening the whole sample is permitted to pass. With limits of 100% passing 1½ in and 95–100% passing 1 in, the maximum size is 1½ in and the nominal maximum size is 1 in. What Is Aggregate and Why Does Gradation Matter? explains why each curve shape behaves the way it does.
Checking against a specification band
A specification band gives a minimum and maximum percent passing for each sieve. A result outside the band on any sieve misses the grading limit on that sieve, even if the fineness modulus looks fine. Plotting both limits on the gradation chart shows at a glance where a sample sits.
Missing a grading limit is not always the end of the matter. As summarised by ACI, ASTM C33 allows fine aggregate that fails the grading requirements to be accepted if concrete made with it is shown to perform at least as well as concrete made with a conforming sand from a source with an acceptable record.
ASTM C33 also limits the material finer than the No. 200 sieve, measured by washing (ASTM C117): 3% for fine aggregate in concrete subject to abrasion and 5% for other concrete, with higher limits for manufactured sand whose fines are free of clay or shale.
| Sieve | Opening | ASTM C33 fine aggregate, % passing |
|---|---|---|
| No. 4 | 4.75 mm | 95–100 |
| No. 8 | 2.36 mm | 80–100 |
| No. 16 | 1.18 mm | 50–85 |
| No. 30 | 600 µm | 25–60 |
| No. 50 | 300 µm | 5–30 |
| No. 100 | 150 µm | 0–10 |
The fineness modulus
The fineness modulus is calculated by summing the cumulative percent retained on a specific standard set of sieves and dividing by 100. It's a single number used to characterize how coarse or fine an aggregate is overall — a higher fineness modulus indicates a coarser gradation. It's commonly used for fine aggregate (sand) grading in concrete mix design.
The standard set runs from the No. 100 sieve up through No. 50, 30, 16, 8 and 4, then 3/8 in, 3/4 in, 1½ in and 3 in, each opening about twice the one below. Sieves outside that series, such as No. 200 or 1/2 in, are left out even if they were used. ASTM C33 calls for concrete sand with a fineness modulus of 2.3 to 3.1 and, for continuing shipments, a variation of no more than 0.20 from the source's base value.
The Sieve Analysis Calculator sums the 3/4 in through No. 100 sieves, which covers sand and any aggregate with nothing retained above 3/4 in.
Checking for a well-graded material
A well-graded aggregate has a reasonably smooth distribution across sieve sizes rather than being concentrated in just one or two sizes (gap-graded) — this typically produces better compaction and strength characteristics for most base and concrete applications. Specification limits (an upper and lower percent-passing bound per sieve) are set by the project or applicable standard and should be checked against, not assumed.
Reading D10, D30 and D60
D10, D30 and D60 are the particle sizes at which 10%, 30% and 60% of the sample passes. D10 is also called the effective size, and it is the size used in Hazen's estimate of the permeability of clean sand.
Each value usually falls between two sieves, so interpolate on the logarithmic size scale: D = d₁ × (d₂ ÷ d₁)^((P − P₁) ÷ (P₂ − P₁)), where d₁ and d₂ are the smaller and larger sieve openings, P₁ and P₂ their percent passing, and P the target (10, 30 or 60). Reading the value off a hand-drawn curve does the same thing graphically.
Cu, Cc and the USCS limits
The coefficient of uniformity is Cu = D60 ÷ D10, and the coefficient of curvature is Cc = D30² ÷ (D10 × D60). The Unified Soil Classification System (ASTM D2487) uses them to separate well-graded from poorly graded gravel and sand when the soil has less than 5% fines.
| Material | Well graded if | Otherwise |
|---|---|---|
| Gravel (more than half of the coarse fraction retained on No. 4) | Cu ≥ 4 and 1 ≤ Cc ≤ 3 (GW) | Poorly graded (GP) |
| Sand (half or more of the coarse fraction passes No. 4) | Cu ≥ 6 and 1 ≤ Cc ≤ 3 (SW) | Poorly graded (SP) |
Example report: a concrete sand
A 600.0 g oven-dry sand sample is washed over the No. 200 sieve, which removes 15 g, then dried and sieved. The table shows the report, with the ASTM C33 band beside each result; the Worked Example below reads it step by step.
| Sieve | Retained (g) | Cumulative retained | % passing | ASTM C33 band |
|---|---|---|---|---|
| 3/8 in (9.5 mm) | 0 | 0.0% | 100 | — |
| No. 4 (4.75 mm) | 18 | 3.0% | 97 | 95–100 |
| No. 8 (2.36 mm) | 66 | 14.0% | 86 | 80–100 |
| No. 16 (1.18 mm) | 96 | 30.0% | 70 | 50–85 |
| No. 30 (600 µm) | 120 | 50.0% | 50 | 25–60 |
| No. 50 (300 µm) | 132 | 72.0% | 28 | 5–30 |
| No. 100 (150 µm) | 102 | 89.0% | 11 | 0–10 |
| No. 200 (75 µm) | 48 | 97.0% | 3.0 | 3 or 5 max. (by washing) |
| Pan | 2 | — | — | — |
Worked Example
Reading the example report above: a 600.0 g sand, washed (15 g removed, 585.0 g after drying), then sieved.
Mass check: the sieves and pan hold 584 g against 585.0 g placed on them, a 1 g (0.17%) difference — inside the 0.3% limit
% passing No. 30: 300 g cumulative ÷ 600 g = 50.0% retained, so 100 − 50.0 = 50% passes
Fineness modulus: (0 + 3.0 + 14.0 + 30.0 + 50.0 + 72.0 + 89.0) ÷ 100 = 2.58, inside 2.3–3.1
Band check: every sieve is inside the C33 band except No. 100 (11% passing against a 10% maximum), so the sand misses the grading limit on that sieve; accepting it would rely on the C33 performance alternative
No. 200: the sieve analysis gives 3.0% total passing, but the C33 limit is checked against the ASTM C117 washing result, 15 ÷ 600 = 2.5% — within both the 3% (concrete subject to abrasion) and 5% (other concrete) limits
D10 (No. 200 at 3%, No. 100 at 11%): 0.075 × (0.15 ÷ 0.075)^((10 − 3) ÷ (11 − 3)) = 0.138 mm
D30 (No. 50 at 28%, No. 30 at 50%): 0.30 × (0.60 ÷ 0.30)^((30 − 28) ÷ (50 − 28)) = 0.320 mm
D60 (No. 30 at 50%, No. 16 at 70%): 0.60 × (1.18 ÷ 0.60)^((60 − 50) ÷ (70 − 50)) = 0.841 mm
Cu = 0.841 ÷ 0.138 = 6.1; Cc = 0.320² ÷ (0.138 × 0.841) = 0.88
With 3.0% passing No. 200 (under 5%), Cu passes the sand limit of 6 but Cc is below 1, so under USCS this is a poorly graded sand (SP), even though its fineness modulus is in range
Assumptions & Limitations
- Percent passing is only as good as the mass check: under ASTM C136, a difference of more than 0.3% between the mass placed on the sieves and the mass recovered means the result should not be used for acceptance.
- D-values interpolated between sieves are estimates; with widely spaced sieves, a small change in percent passing can move Cc across a classification limit.
FAQ
- What does percent passing mean in a sieve analysis?
- It is the percentage of the sample, by dry mass, that is finer than that sieve's opening. It equals 100 minus the cumulative percent retained on that sieve and every larger one.
- How do you find D10 from a sieve analysis?
- Find the two sieves whose percent passing brackets 10%, then interpolate between their openings on a logarithmic scale, or read the size where the gradation curve crosses 10%. D30 and D60 are found the same way.
- What Cu and Cc values mean a material is well graded?
- Under the Unified Soil Classification System, a gravel needs Cu of at least 4 and a sand Cu of at least 6, and both need Cc between 1 and 3. These limits apply to soils with less than 5% fines.
- Why don't my retained masses add up to the sample mass?
- Some dust is always lost and some particles stay stuck in the mesh. ASTM C136 allows a difference of up to 0.3% between the mass placed on the sieves and the mass recovered; beyond that, check for spillage or a weighing error before using the result.
- Can a sand meet ASTM C33 and still be poorly graded?
- Yes. C33 checks percent passing against grading limits and the fineness modulus, while USCS uses Cu and Cc. A concrete sand can sit inside the C33 band and still classify as SP, because the two systems answer different questions.
Related Calculators
Related Guides
From the Blog
Sources
ASTM C136
Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates.
ACI Education Bulletin E1-07, Aggregates for Concrete
Sieve-analysis reporting, the 0.3% mass check, fineness-modulus sieves, C33 fineness-modulus range and No. 200 limits.
ACI Education Bulletin E1-07, Aggregates for Concrete — referenceFHWA-HRT-06-117, Appendix A
ASTM C33 fine-aggregate grading limits (Tables 22–24).
FHWA-HRT-06-117, Appendix A — referenceFHWA NHI-05-037, Table 4-13
Unified Soil Classification System criteria, including Cu and Cc limits (after ASTM D2487).
FHWA NHI-05-037, Table 4-13 — reference