This program is designed to estimate the amounts (weight in pounds or
volume in gallons) of different components in a composting mixture to
achieve a desired C/N Ratio and/or % Moisture. The weight
calculation requires estimated properties of the components: PN
(percentage Nitrogen based on Dry Weight), C/N (Carbon to Nitrogen
Ratio w/w), and Percentage Moisture in the component as it is
mixed. The densities (pounds/gallon) of the bulk components are
needed for mixing by volume, which is usually more convenient for home
A table of these properties for some common materials is
There is a provision for two other ("New") materials to be added, as
well as a combination ("Mixture") of two components. This
added information is not stored by the computer, and is lost on
re-starting or Refreshing the Web Page.
Calculating C/N and Moisture % from Known Amounts:
1. Click the button to select this
option. This automatically puts "5" in the blank
beside "component 1", clears the
amount of component 2, and shows that these
quantities will be
2. Select the desired materials as "Component 1" and
3 Edit the blank beside "component1" if a different
amount is wanted, and enter a value
for "component 2".
4. Make sure that the desired units ("Gal" or "Lbs")
is selected and click on "Calculate".
5. The calculated values appear.
6. If you want to add another component, click on
"Save Mixture". The calculated values
for the mixture appear in
the table of properties. The mixture can then be selected as a
component for further
7. Repeat step 6 to add more materials.
Adding New Materials:
1. To add new materials, you must have
estimates of the of the Percentage Moisture,
Percentage Nitrogen, C/N
Ratio, and possibly the Bulk Density of the material. A
large collection of such values
is at :
On-Farm Composting Handbook - eXtension Online Campus
2. Enter appropriate values in Line 10 or 11
and click on "Save New Data".
3. These added materials may be replaced by
replacing the data and clicking on
"Save New Data".
Calculate the Amount of Component 2 Needed for Desired C/N Ratio or
1. These calculate the amount of component 2 to be
mixed with a specified amount of
component 1 to achieve a
specific value of either C/N Ratio or Moisture %.
2. Click on the desired Type of
Calculation. Enter appropriate values for the amount of
component 2 and the desired
outcome in the blank spaces. Click on "Calculate" and
the required amount of
component 2 will appear in the upper "calculate" space, and the
corresponding result will
appear in the lower "calculate" space.