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Logistic Growth

dNdt=rmaxN(K-NK)
(rmax)per capita growth
(N)population size
(K)carrying capacity
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The Logistic Growth calculator computes the logistic growth based on the per capita growth rate of population, population size and carrying capacity.

INSTRUCTIONS: Choose units and enter the following:

  • (rmax) Maximum per capita Growth Rate of population
  • (N) Population Size
  • (K) Carrying Capacity

Logistic Growth (dN/dt): The calculator returns the logistic growth rate in growth per day.   However, this can be automatically converted to compatible units via the pull-down menu (e.g. growth per month).

The Math / Science

The growth rate of a population without constraints is exponential, where every new organism can reproduce at the rate it was produced.  In reality, resources often limit the growth of a population as population sizes reach the limits that can be sustained by the resources available at hand.  For this reason, a purely exponential model is inaccurate and a model that flattens as it reaches the capacity of the environment is more useful.  The logistic growth model is one.  It produces an s-shaped curve that maxes out at a boundary defined by a maximum carrying capacity. 

The logistic growth formula is:

     dNdt=rmaxN(K-NK)

where:

  1. dN/dt - Logistic Growth
  2. rmax - maximum per capita growth rate of population
  3. N - population size
  4. K -  carrying capacity


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