What Are D10 and D90?

D10 and D90 are particle size distribution metrics where D10 is the particle diameter below which 10% of the sample mass falls and D90 is the diameter below which 90% of the sample mass falls, together defining the spread or width of a particle size distribution. Combined with D50 (the median), D10 and D90 provide a concise three-number characterization of any bulk material's size distribution. These values are derived from sieve analysis, laser diffraction, or other particle sizing methods.

D10 characterizes the fine tail of the distribution — the smallest 10% of particles by mass. D90 characterizes the coarse tail — only 10% of the material is larger than the D90 value. The ratio (D90 - D10) / D50, known as the "span," quantifies how narrow or broad the distribution is. A narrow-span material (span under 1.0) has particles tightly grouped around the median size, while a broad-span material (span over 2.0) contains a wide range of particle sizes from very fine to very coarse.

D10, D50, D90 Example Distributions

Why This Matters in Vibratory Screening

D10 and D90 values reveal critical information about how your material will behave on a vibratory screener — information that D50 alone cannot provide.

• Blinding prediction — When D90 is within 20% of your screen opening, a large proportion of the material is near-size, which dramatically increases blinding risk. You may need ultrasonic de-blinding, ball trays, or a different mesh approach.
• Throughput estimation — A narrow distribution (low span) with D50 well below the screen opening will screen fast and efficiently. A broad distribution requires more screening area or multi-deck separation to achieve the same result.
• Multi-deck configuration — The D10 and D90 values help determine how many decks are needed. If D90 is 2,000 microns and D10 is 50 microns, you may need a top deck at 10 mesh for scalping and a bottom deck at 200 mesh for fines removal.
• Product specification — Many pharmaceutical, food, and chemical specifications define both D50 and D90 limits (for example, "D50: 100-150 microns, D90: max 300 microns"). Your vibratory screener must enforce the D90 limit by removing all material above that size.

Related Glossary Terms

• D50 Particle Size — The median particle size (50th percentile)
• Sieve Analysis — The test method for determining D10, D50, and D90
• Screening Efficiency — Performance metric influenced by distribution width
• Blinding — Screen clogging caused by near-size particles
• Mesh Size — Screen opening specification correlated to Dx values
• RoTap Sieve Shaker — Lab equipment for generating sieve analysis data

D10, D90 FAQs

What do D10 and D90 mean?

D10 is the particle size at which 10% of the material by mass is finer — it characterizes the fine end of the distribution. D90 is the particle size at which 90% of the material is finer — it characterizes the coarse end. Together with D50, they describe the full width of the particle size distribution.

How do D10 and D90 affect vibratory screening?

D10 and D90 values determine how much of your material is near the screen opening size, which directly affects throughput, screening efficiency, and blinding risk. If D90 is close to your screen mesh opening, nearly all the material is near-size, which causes high blinding and low throughput. If D10 is well below the screen opening, most fines will pass quickly.

What is the span of a particle size distribution?

The span is calculated as (D90 - D10) / D50 and measures how wide the particle size distribution is relative to the median. A span of 1.0 or less indicates a narrow distribution, while a span above 2.0 indicates a broad distribution. Narrow distributions are generally easier to screen because fewer near-size particles exist at any given mesh opening.