How do you calculate grind-size test throughput?

Divide the sample weight by the test runtime, then multiply by efficiency. A 24 lb sample over 2 hours is 12 lb/hr raw; at 85% efficiency the effective throughput is 10.2 lb/hr.

What does the testing efficiency factor represent?

It captures lost lab time — handling, weighing, cleaning sieves, and recording — that makes real throughput lower than the raw rate. At 85% efficiency you keep 10.2 of the raw 12 lb/hr.

Why measure grind size by throughput rather than just the result?

Throughput tells you how often you can sample. If effective capacity is only 10.2 lb/hr, you know whether your sampling plan keeps up with the mill or needs a faster shaker.

What is a good particle-size test efficiency?

Manual sieve work commonly lands at 80-90% efficiency once you net out weighing and cleaning. Automated analyzers push higher. Benchmark against your own lab's logged times.

How can I raise effective grind-test throughput?

Cut non-test time — pre-weighed samples, faster sieve cleaning, or an automated particle-size analyzer raise the efficiency factor and lift effective lb/hr without changing the test itself.

Grind size distribution vs mean particle size — what is the difference?

Mean particle size is a single average; the distribution shows how particles spread across sieve fractions. This tool sizes how fast you can run the test, not which metric you report.

Grain Milling, Dry Bulk Food & Feed Handling calculator

Grind Size Distribution Calculator

This calculator turns a grind-size (particle-size) sieve test into a throughput rate, telling you how many pounds of ground sample your lab effectively screens per hour once test efficiency is accounted for. Mill quality technicians and process engineers at flour and feed mills use it to plan how often they can sample the grind without falling behind production, and to right-size lab staffing for particle-size control. Because feed conversion, pellet durability, and flour functionality all hinge on consistent particle size, knowing your real testing cadence matters as much as the test result itself. It converts a single sieve shake into a defensible lab capacity number.

What this calculator does

Estimate the practical rate for completing grind-size distribution checks by comparing sample weight processed through sieves or particle-size testing with test runtime and lab efficiency.
Use it when quality or production needs to understand how quickly hammer mill, roller mill, pellet crumble, or flour particle-size samples can be checked during a run.
It divides sample weight by sieve test runtime to get raw test throughput, then multiplies by an efficiency factor to give effective lb/hr.

Formula used

Raw grind-size test throughput = sample weight tested ÷ particle-size test runtime
Effective grind-size test throughput = raw throughput × testing efficiency

Inputs explained

Ground sample weight tested:
Particle-size sieve test runtime:
Sieve test efficiency factor:

How to use the result

Use it when planning grind-size sampling frequency, sizing lab capacity, or justifying a faster sieve shaker or automated particle-size analyzer.
It treats efficiency as a flat factor and does not model sieve blinding, static, or fines that distort heavier samples — it sizes lab throughput, not the accuracy of the distribution itself.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
Industrial natural gas averages $4.9 per Mcf (EIA, Apr 2026), down 7.7% from a year earlier, with industrial electricity at 8.66 cents per kWh. Process heating and refrigeration budgets track both.
The U.S. has 17,154 machine shops establishments employing about 223,303 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate grind-size test throughput? Divide the sample weight by the test runtime, then multiply by efficiency. A 24 lb sample over 2 hours is 12 lb/hr raw; at 85% efficiency the effective throughput is 10.2 lb/hr.
What does the testing efficiency factor represent? It captures lost lab time — handling, weighing, cleaning sieves, and recording — that makes real throughput lower than the raw rate. At 85% efficiency you keep 10.2 of the raw 12 lb/hr.
Why measure grind size by throughput rather than just the result? Throughput tells you how often you can sample. If effective capacity is only 10.2 lb/hr, you know whether your sampling plan keeps up with the mill or needs a faster shaker.
What is a good particle-size test efficiency? Manual sieve work commonly lands at 80-90% efficiency once you net out weighing and cleaning. Automated analyzers push higher. Benchmark against your own lab's logged times.
How can I raise effective grind-test throughput? Cut non-test time — pre-weighed samples, faster sieve cleaning, or an automated particle-size analyzer raise the efficiency factor and lift effective lb/hr without changing the test itself.

Last reviewed 2026-05-12.