How to Calculate Stone Crushing Plant Capacity (TPH) Before You Buy

Why Capacity Calculations Come First

Before you buy any crusher, you need one number: the capacity your plant must deliver, in tons per hour (tph). Every crusher, screen and conveyor in the plant is sized from this number. Ordering equipment before doing the calculation is the most common reason plants end up undersized — batching behind the crusher, wasting fuel and missing delivery deadlines. This guide walks through a simple five-step method to calculate the capacity you need and match the right equipment to it.

Step 1: Define the Raw Material

Start with the rock itself. Measure the maximum feed size (the largest boulder entering the plant), the compressive strength, and the moisture and clay content. Hard, abrasive rock such as granite and basalt needs heavier crushers; sticky or wet feed needs larger openings and careful screening. These three characteristics — size, hardness, moisture — determine which crushers can handle the material at all.

Step 2: Set the Target Output

Work backwards from your daily requirement. If you must deliver 1,000 tons of finished aggregate per day and plan 10 operating hours, the plant needs 100 tph average capacity. Add 10–20% as a safety factor for surge, downtime and harder-than-expected material — so a realistic spec is 110–120 tph. Never spec exactly to the average; crushers rarely run at 100% efficiency every hour.

Step 3: Match the Primary Crusher

The jaw crusher must accept the largest feed boulders without bridging. Check that the feed opening is roughly 15–20% larger than the biggest rock, then confirm the rated capacity at the closed-side setting you plan to run. For example, a plant crushing mountain stone at 100–150 tph typically uses a jaw crusher sized for that duty, and our 100–150 tph hard stone flow chart shows a realistic configuration.

Step 4: Match Secondary Crushing and Screening

The secondary crusher — usually a cone crusher or impact crusher — must handle the full primary output plus any recycled oversize from the screen. Size the screen to separate the required product sizes and return oversize to the secondary crusher in a closed circuit. A common mistake is sizing the screen from the feed rate instead of the circulating load, which can be 30–50% higher.

Step 5: Account for Real-World Factors

• Moisture and clay — reduce effective capacity and can clog screens and chutes.
• Gradations — a well-graded feed lets a crusher reach its rated capacity; all-fines or all-oversize feed does not.
• Operating hours — a 20-hour operation can use a smaller plant than an 8-hour operation for the same daily tonnage.
• Future expansion — allow space and spare capacity if you expect to grow production later.

Sample Capacity Planning Table

FAQ

Q: What is the safety factor when calculating crusher capacity?

A: Most plants add 10–20% above average tph to cover surges and downtime. Confirm the final factor with your equipment supplier.

Q: How is crusher capacity measured?

A: In tons per hour at a given closed-side setting and feed gradation. Always compare capacities under the same conditions — datasheet figures usually assume ideal feed.

Q: Can I expand my plant capacity later?

A: Yes. Many plants add a second crusher, a bigger screen or an additional stage later. Plan the layout and conveyors for expansion from day one.

Conclusion: Calculate First, Buy Second

A clear capacity calculation protects your investment and keeps the plant running at target. MGM provides 100 tph mountain stone, 150 tph hard stone and 250 tph hard stone flow charts, and our engineers will help you size the right plant for your material. Contact MGM with your daily target, feed size and rock type for a free capacity plan.