Enter Belt and Material Data
Formula used
The calculator uses a practical conveyor estimate. It combines section area, density, speed, incline correction, sag, and tension margin.
A = Weff² × K × F
Lm = A × ρ × M × Ci
Q = Lm × V × 3.6 × η
Sag % = ((Lt × 9.81 × Idler spacing) / (8 × T)) × 100
Safety factor = Rated tension / (Operating tension × Dynamic factor)
Here, A is carrying area. Weff is effective belt width. K is the trough and surcharge shape factor. F is fill factor. Lm is material line load. Q is tonnes per hour. η is drive efficiency.
How to use this calculator
- Enter belt width, belt speed, density, and profile angles.
- Add realistic fill factor, edge clearance, moisture allowance, and incline.
- Enter belt self weight, idler spacing, live load rating, and tension values.
- Press the calculate button and review the result block above the form.
- Use the CSV or PDF button to save the result for project notes.
Example data table
| Case | Width | Speed | Density | Fill | Typical use |
|---|---|---|---|---|---|
| Light aggregate | 650 mm | 1.8 m/s | 1350 kg/m³ | 65% | Small site conveyor |
| Crushed stone | 800 mm | 2.2 m/s | 1600 kg/m³ | 75% | General construction handling |
| Wet sand | 1000 mm | 2.5 m/s | 1900 kg/m³ | 70% | Heavier loading check |
Practical Belt Capacity Planning
A belt conveyor is often sized by more than width. It must carry enough material without overloading the belt, idlers, drive, or supports. A good check starts with material density, belt speed, and the usable carrying area. Then it compares the produced load with ratings that protect the system.
Why Line Load Matters
Line load is the mass placed on each meter of belt. It affects sag between idlers. It also affects frame reactions and pulley demand. A high hourly capacity can still be unsafe when the load per meter is too high. That is why this calculator reports both tonnes per hour and kilograms per meter.
Key Design Inputs
Bulk density controls the weight of the material stream. Belt speed controls how much of that stream passes a point each second. Fill factor represents how much of the belt profile is actually used. Troughing angle, surcharge angle, and edge clearance shape the usable section. Incline reduces practical carrying ability because material may slide, roll back, or form an unstable pile.
Safety Review
The calculator compares calculated line load with the entered live load rating. It also estimates sag from load, idler spacing, and operating tension. Smaller idler spacing usually reduces sag. Higher tension also reduces sag, but it must remain inside the rated belt limit. The dynamic factor adds allowance for starting, stopping, impact, and uneven feed.
Construction Use
Use this page during concept estimates, site planning, or conveyor replacement checks. It helps compare alternate belt widths, speeds, and material densities. It can also show when a capacity target needs a wider belt, slower loading, stronger idlers, or a lower incline. The results support discussion. They do not replace manufacturer data or a project engineer.
Good Practice
Enter conservative values when the site is dusty, wet, or variable. Use the heaviest expected density. Add moisture allowance when material can absorb water. Keep fill factor realistic. A belt that is always filled to the edge may spill and wear fast. Review guarding, emergency stops, foundations, and maintenance access before final installation.
Interpreting Output
If the recommended capacity is below the geometric capacity, another limit controls the system. Check the warning cards first. They point to sag, rating, tension, or incline concerns before procurement decisions are made.
FAQs
1. What does belt load-carrying capacity mean?
It is the practical amount of material the belt can carry safely. This page estimates capacity by using belt geometry, density, speed, load rating, sag, and tension inputs.
2. Why is line load shown in kg/m?
Line load shows how much mass sits on each meter of belt. It affects sag, idlers, frame reactions, and support design.
3. Is tonnes per hour enough for design?
No. Hourly capacity is useful, but line load and tension checks are also important. A high flow rate can overload the belt between idlers.
4. What fill factor should I use?
Use a realistic value based on loading control and material behavior. Many preliminary checks use a moderate value instead of assuming the belt is fully loaded.
5. How does incline angle affect the result?
Incline reduces practical carrying ability. Steeper belts can cause rollback, sliding, or unstable material piles. The calculator applies an incline correction.
6. Why enter moisture allowance?
Moisture can raise bulk density. Wet sand, soil, and aggregate may weigh more than dry values. The allowance adds a conservative density increase.
7. What does estimated sag mean?
Sag is the belt dip between idlers under load. High sag can increase spillage, wear, tracking issues, and structural demand.
8. What is the dynamic factor?
The dynamic factor allows for starting, stopping, impact, uneven feed, and short load surges. It raises the effective tension demand.
9. Can this replace manufacturer data?
No. Use it for preliminary construction planning and comparison. Final conveyor design should follow supplier data, site conditions, and engineering review.
10. Why is recommended capacity lower than geometric capacity?
Another limit may control the system. Live load rating, allowable sag, or dynamic tension safety can reduce the recommended capacity.
11. What values should I use for early estimates?
Use conservative values. Choose heavy density, realistic fill, actual belt speed, likely incline, and a safety factor suitable for the project risk.