Composting Windrow Volume Calculator

Work out composting windrow volume instantly with clear inputs, formula shown and shareable results.

About Composting Windrow Volume Calculator

The mass in active composting is daily feedstock times the composting period. Dividing by bulk density gives volume, and by the windrow cross-section gives total windrow length. Adding turning aisles roughly doubles the footprint, so pad area is typically 3-4 square metres per metre of windrow.

Formula

Windrow length

Volume = mass in process x 1000 / bulk density; length = volume / cross-sectional area

Worked example

With the default values below, Composting Windrow Volume Calculator returns Windrow Length Required of 242.4. Change any input above and every figure here is recalculated in your browser.

Inputs used

Daily Feedstockminimum 0 tonnes/day: 20 tonnes/day
Active Composting Periodminimum 0 days: 30 days
Feedstock Bulk Densityminimum 0 kg/m3: 550 kg/m3
Windrow Cross-Sectional Areaminimum 0 m2: 4.5 m2

Results

Windrow Length Required: 242.4
Material Volume In Process: 1,090.9
Mass In Process: 600.00
Pad Area Including Aisles: 848.5

Step by step

1Values used
2Windrow length
3Windrow Length Required= 242.4
4Material Volume In Process= 1,090.9
5Mass In Process= 600.00
6Pad Area Including Aisles= 848.5

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation or tax into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Composting of animal by-products and food waste is subject to specific sanitisation and record-keeping requirements. Confirm the applicable regulations.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Composting of animal by-products and food waste is subject to specific sanitisation and record-keeping requirements. Confirm the applicable regulations.

Frequently Asked Questions

What windrow size is optimal?

Typically 2-2.5 m high and 3-4 m wide. Larger windrows go anaerobic in the core; smaller ones lose heat and fail to reach the sanitising temperature.

What temperature must be reached?

Regulations generally require 55 C for three consecutive days with turning, or similar, to sanitise pathogens and weed seeds. Temperature records are a compliance requirement.