Enter the Gross Primary Productivity (GPP) and the Respiration Loss (R) into the calculator to determine the Net Primary Productivity (NPP). This calculator helps in understanding the efficiency of an ecosystem in converting carbon dioxide into organic compounds.

Net Primary Productivity Formula

The following formula is used to calculate the Net Primary Productivity.



  • NPP is the Net Primary Productivity (gC/m²/yr)
  • GPP is the Gross Primary Productivity (gC/m²/yr)
  • R is the Respiration Loss (gC/m²/yr)

To calculate the Net Primary Productivity, subtract the Respiration Loss from the Gross Primary Productivity.

What is Net Primary Productivity?

Net Primary Productivity (NPP) is the rate at which all the plants in an ecosystem produce net useful chemical energy; it is equal to the difference between the energy produced through photosynthesis (GPP) and the energy used up during respiration (R). NPP represents the amount of organic matter available for consumption by heterotrophic organisms (herbivores and decomposers).

How to Calculate Net Primary Productivity?

The following steps outline how to calculate the Net Primary Productivity.

  1. First, determine the Gross Primary Productivity (GPP) in grams of carbon per square meter per year (gC/m²/yr).
  2. Next, determine the Respiration Loss (R) in grams of carbon per square meter per year (gC/m²/yr).
  3. Use the formula NPP = GPP – R to calculate the Net Primary Productivity.
  4. Finally, enter the values of GPP and R into the calculator to get the NPP.

Example Problem :

Use the following variables as an example problem to test your knowledge.

Gross Primary Productivity (GPP) = 1000 gC/m²/yr

Respiration Loss (R) = 600 gC/m²/yr