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Tool: pure arithmetic

Belt feed-rate calculator

The feed rate reaching your separator, from belt speed, how much material the belt carries and its bulk density. You get volume and tons per hour, with the formula and your numbers written out.

It does not size equipment or pick a machine. Updated

Calculator

Units
ft/min

Measured along the belt.

Material on the belt
Material cross-section on a flat belt A slice across a flat belt. The material forms a shallow band of width w and average depth d. Its area, A, is roughly w times d. A w d
Figure 1. One slice across a flat belt carrying an even layer: A is about w × d. Schematic, not to scale.
in
in

Fill both and the cross-section below is worked out for you: A = w × d ÷ 144.

ft²

The area of material in one slice across the belt, as drawn above. Enter it directly if you know it.

lb/ft³

Loose weight per unit volume, as it sits on the belt. Published figures, for material in bulk rather than a layer on a belt, run from about 1.7 to 3.4 lb/ft³ (27 to 54 kg/m³) for loose cans (US EPA conversion tables, 2016 and 2006) to about 52 to 100 lb/ft³ (830 to 1,600 kg/m³) for crushed or broken glass cullet (US EPA, 2006). More streams, with sources: bulk density reference.

Volume per hour

3,000ft³/h

Feed rate by mass

15.0US tons/h

30,000 lb/h

VolumeQ = A × v × 60 = 0.5 ft² × 100 ft/min × 60 = 3,000 ft³/h
MassM = Q × ρ ÷ 2,000 = 3,000 ft³/h × 10 lb/ft³ ÷ 2,000 = 15.0 US tons/h

A steady-state average. It does not account for surges, and it does not say whether any machine can handle this rate.

Use this rate in an RFQ

Not sure about an input? Check this rate with an engineer at Remcon Equipment, the publisher's affiliate.

Who publishes this. Recyclers Guide is published by [LLC name], an affiliate of Remcon Equipment, Inc. Remcon designs and builds conveyors and eddy current separator systems around rotors or complete separators made by others, builds overhead magnet units, magnetic head pulleys and trommels, resells screens and feeders, and integrates equipment discussed on this site.

1What the cross-section means

Cut an imaginary slice across the belt and look at it end-on. The material in that slice has an area, A. Multiply it by how fast the belt moves and you have the volume passing per unit of time.

Figure 1, in the calculator above, draws that slice. For a flat belt carrying an even layer, A is about the band width w times its average depth d. For a troughed belt or a heaped load, work out or measure the actual area.

2The formula

Volume flow is area times speed. Mass flow is volume flow times bulk density. The constants only convert minutes or seconds to hours, and pounds or kilograms to tons.

ImperialQ (ft³/h) = A (ft²) × v (ft/min) × 60
M (US tons/h) = Q × ρ (lb/ft³) ÷ 2,000
MetricQ (m³/h) = A (m²) × v (m/s) × 3,600
M (t/h) = Q × ρ (kg/m³) ÷ 1,000

Eriez prints the same arithmetic for its vibratory feeders: Q (tons/h) = W × d × D × v ÷ 4,800, with tray width W and depth d in inches, bulk density D in lb/ft³ and speed v in ft/min. Put A = w × d ÷ 144 into the imperial formula above and its constants come to the same divisor: 144 × 2,000 ÷ 60 = 4,800. Source: Eriez, SM-780-1 separator manual, 2010, and VM-3660C feeder manual, 2009 (3, 4).

3Worked example

These inputs are hypothetical, chosen so the arithmetic is easy to follow. They are not typical values for any material. The speed, area and density are also the calculator's starting values, so you can check it against this page.

Imperial, step by step (hypothetical inputs)
StepArithmeticResult
Inputsv = 100 ft/min, w = 24 in, d = 3 in, ρ = 10 lb/ft³
Cross-section24 × 3 ÷ 1440.5 ft²
Volume per minute0.5 × 10050 ft³/min
Volume per hour50 × 603,000 ft³/h
Mass per hour3,000 × 1030,000 lb/h
In US tons30,000 ÷ 2,00015.0 US tons/h

A metric example: 0.05 m² × 0.5 m/s × 3,600 = 90 m³/h, and 90 × 200 kg/m³ ÷ 1,000 = 18.0 t/h. A width and depth in millimetres give the area as w × d ÷ 1,000,000. Switching units in the calculator converts whatever is in the boxes.

4What this does not tell you

  • Whether a separator can handle the rate. Ask each manufacturer for its rated range with your material.
  • How much a belt can carry. That depends on belt width, troughing and how high material can pile before it spills or, on a sorting line, before pieces overlap.
  • Surges. The result is an average. Size for the peak you actually see.

On a sorting line the limit is usually burden depth, not belt capacity. See designing an aluminum line.

5Sources

  1. US Environmental Protection Agency, Office of Resource Conservation and Recovery. Volume-to-Weight Conversion Factors (memorandum). April 2016. Government; compiles figures from other organizations. https://www.epa.gov/sites/default/files/2016-04/documents/volume_to_weight_conversion_factors_memorandum_04192016_508fnl.pdf. Read 2026-10-06.
  2. US Environmental Protection Agency. Standard Volume-to-Weight Conversion Factors. Table last updated February 28, 2006. Government; compiles figures from other organizations. https://www.epa.gov/sites/default/files/2016-03/documents/conversions.pdf. Read 2026-10-06.
  3. Eriez. SM-780-1, Eddy Current Separator, REA Cartridge Design: installation, operation and maintenance manual. 2010. Manufacturer. https://www.eriez.com/Documents/Literature/IOMs/Metals-Recycling/SM-780-1-Eriez-Eddy-Current-Separator-REA-Cartridge-Design-IOM.pdf. Read 2026-10-06.
  4. Eriez. VM-3660C, Brute Force Feeder: installation, operation and maintenance manual. 2009. Manufacturer. https://eriez.com/Documents/Literature/IOMs/Vibratory-Feeders-and-Conveyors/VM-3660-Eriez-Brute-Force-Feeder-IOM.pdf. Read 2026-10-06.

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