How do I work out what size conveyor I need?

Working out the right size conveyor for your operation is crucial for efficient bulk material handling. Whether you’re in recycling, construction, or manufacturing, choosing the correct conveyor size can save you time, money, and a lot of hassle down the line. In this guide, we’ll cover the key factors, provide a simple conveyor capacity calculator and answer the most common questions about conveyor sizing.

Why Conveyor Size Matters

Picking the correct conveyor size ensures your system can handle the required throughput without bottlenecks or spillage. Oversized conveyors waste energy and space, while undersized belts lead to blockages and downtime. That’s why it’s essential to get the calculation right from the start.

Key Factors in Conveyor Sizing

• Material type: Is it fine, free-flowing, sticky, or chunky? Bulk density and flow characteristics will affect your choice.
• Required capacity: How many tonnes per hour do you need to move?
• Conveyor length and incline: Distance and elevation changes impact the design.
• Belt width: Wider belts move more material but take up more space and power.
• Belt speed: Faster belts increase capacity but can cause spillage if not matched to material type.
• Material thickness: The average depth of material on the belt.
• Fill factor: Usually 0.6 (60%), reflecting the belt not being 100% full.

Conveyor Capacity Calculator

Use this simple formula to estimate your conveyor’s capacity:

Capacity (tonnes/hour) = Belt Speed (m/s) × Belt Width (m) × Material Thickness (m) × Bulk Density (tonnes/m³) × 3,600 × Fill Factor

Example Calculation:

• Belt Speed = 1.2 m/s
• Belt Width = 0.5 m
• Material Thickness = 0.15 m
• Bulk Density = 1.6 tonnes/m³
• Fill Factor = 0.6
• 
  

Capacity = 1.2 × 0.5 × 0.15 × 1.6 × 3,600 × 0.6 = 311 tonnes/hour

Note: The “3,600” factor converts from per second to per hour. Always check your units—this formula gives you tonnes per hour, not kilograms.

Step-by-Step: How to Choose the Right Conveyor Size

1. Identify your material: Is it sand, aggregate, wood waste, or something else? Know its bulk density.
2. Estimate required throughput: How much material do you need to move per hour?
3. Measure site constraints: Length, height, and available space.
4. Decide on belt width and speed: Use the calculator above to test different options.
5. Consider practicalities: Maintenance access, power supply, and environmental factors like dust or moisture.

Common Conveyor Sizing Questions (FAQ)

• What factors affect conveyor capacity?
  Material type, belt width, speed, thickness, and fill factor all play a role.
• Can I use this formula for any material?
  Yes, as long as you know the bulk density and adjust the fill factor for your application.
• What’s the standard fill factor?
  0.6 (60%) is typical, but it may vary for sticky or lumpy materials.
• How do I avoid spillage?
  Don’t run belts too fast for the material type, and make sure the belt width matches your throughput needs.

Practical Considerations for Conveyor Installation

• Space on site: Will the conveyor fit where you need it? Watch out for tight corners and overhead obstructions.
• Maintenance access: Make sure there’s room to get at bearings, motors, and belts for servicing.
• Power supply: Check you’ve got the right electrics or hydraulic supply for the drive system.

Why Choose Spitfire Engineering?

With over 20 years’ experience in bespoke recycling equipment, Spitfire Engineering offers expert advice and custom conveyor solutions for every site—from small skip yards to major recycling plants. We help you get the size right, first time.



Ready to spec your conveyor?