Rock Crusher Sizing Guide: Choosing the Right Type and Capacity for Your Material
How to size a rock crusher to your material and tonnage — jaw vs. cone vs. impact, feed size, and capacity — so you buy the right machine the first time.
Buy a crusher that's too small and you'll bottleneck your whole operation. Buy one that's too big and you've tied up capital and fuel you didn't need. Sizing a rock crusher correctly — the right type and the right capacity for your material and tonnage — is the difference between a machine that pays for itself and one that frustrates you daily. Here's how to get it right the first time.
Step 1: Match the crusher type to the job
The three main crusher types do different work. Most operations that run a lot of material use more than one in sequence.
Jaw crusher — primary reduction. Jaws are the workhorse first stage. They take large, hard feed (blasted rock, concrete, oversize) and reduce it to a manageable size. Rugged, tolerant of abrasive and hard material, and the natural choice for the first crushing stage. Reduction ratio is modest (roughly 6:1), so a jaw alone won't get you to a finished spec product.
Cone crusher — secondary/tertiary shaping. Cones take the jaw's output and reduce it further into cubical, spec-sized product. They excel on hard, abrasive stone (granite, basalt, trap rock) and are how you make clean aggregate sizes. They need consistent feed and don't like tramp metal.
Impact crusher (HSI) — versatile reduction, softer material. Impactors deliver a high reduction ratio and good product shape in a single machine, which makes them popular for concrete and asphalt recycling and softer/medium stone. They can often skip a stage. The trade-off is faster wear on hard, abrasive rock — blow bars don't last on granite the way they do on concrete.
Quick rule of thumb:
- Hard, abrasive rock, making spec aggregate → jaw + cone
- Concrete/asphalt recycling, C&D → impact (often single-stage)
- Soft-to-medium stone, high reduction wanted → impact
Step 2: Size the capacity to your tonnage
Once the type is right, size the throughput. Get this from three inputs:
1. Your required tons per hour (TPH). Be honest about sustained production, not a peak-hour number. If you need 200 TPH of finished product, don't size the primary for exactly 200 — build in headroom.
2. Your feed size. The crusher's opening (a jaw's gape, expressed as something like 32"x42") has to comfortably accept your largest feed material. If your feed is bigger than the machine can swallow, you'll bridge and choke constantly. Match the opening to your actual top-size, plus margin.
3. Your closed-side setting (CSS) and product spec. Tighter settings make smaller product but reduce throughput. The TPH a manufacturer quotes is always tied to a specific setting and material — read the spec sheet carefully, because "300 TPH" at a wide-open setting on soft rock may be 120 TPH at your actual spec.
Step 3: Don't forget the rest of the circuit
A crusher is only as productive as the machines around it. Undersize the feeder, the screen, or the conveyors and the crusher starves or backs up. A balanced circuit — feeder, crusher, screen, stacker sized to work together — is what actually delivers the tonnage on paper.
Step 4: Mobile vs. stationary, tracked vs. wheeled
- Tracked mobile crushers move around a site or between jobs under their own power — ideal for contractors, recyclers, and anyone who relocates often.
- Wheeled portable plants suit operations that move occasionally but set up for longer runs.
- Stationary makes sense only for a fixed quarry with predictable, high-volume production.
For most contractors and recyclers, a tracked mobile jaw (with a cone or screen behind it) is the flexible, resale-friendly choice.
Get it sized right before you buy
The most expensive crusher mistake is buying the wrong size or type for the material — and then living with the bottleneck for years. Before you commit, it's worth talking through your material, your target TPH, and your product spec with someone who sizes these circuits regularly.
At RPG Equipment we broker crushers, screeners, and conveyors across every major brand, and we'll help you match the machine to the job — not just sell you what's on the lot. Tell us your material and tonnage and we'll point you to the right unit. Call (413) 478-2525 or browse current crushers at rpgequipment.com/equipment/crushers.
RPG Equipment is a heavy equipment brokerage based in Worcester, MA specializing in grinders, crushers, screeners, and material processing equipment. Contact us to buy or sell equipment, or browse more articles.