Enter the total weight of carbon (lbs) and the total weight of nitrogen (lbs) into the Compost Ratio Calculator. The calculator will evaluate and display the Compost Ratio. 

Compost Ratio Formula

The following formula is used to calculate the Compost Ratio. 

COMPR = WC / WN
  • Where COMPR is the Compost Ratio
  • WV is the total weight of carbon (lbs) 
  • WN is the total weight of nitrogen (lbs) 

To calculate the compost ratio, divide the total weight of carbon by the total weight of nitrogen.

The ideal ratio is roughly 30:1 carbon to nitrogen.

How to Calculate Compost Ratio?

The following example problems outline how to calculate Compost Ratio.

Example Problem #1:

  1. First, determine the total weight of carbon (lbs).
    • The total weight of carbon (lbs) is given as: 500.
  2. Next, determine the total weight of nitrogen (lbs).
    • The total weight of nitrogen (lbs) is provided as: 20.
  3. Finally, calculate the Compost Ratio using the equation above: 

COMPR = WC / WN

The values given above are inserted into the equation below and the solution is calculated:

COMPR = 500 / 20 = 25:1

Example Problem #2: 

For this problem, the variables required are provided below:

total weight of carbon (lbs) = 600

total weight of nitrogen (lbs) = 20

Test your knowledge using the equation and check your answer with the calculator above.

COMPR = WC / WN = ?