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Capture Recapture Method

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The Capture Recapture Method of sampling is used to try and estimate the entire population. A sample of animals are caught and tagged, their number noted, and then released back into their habitat. Later another sample is captured and the proportion of tagged animals in this sample should be representative of the proportion of tagged animals in the whole population, and then the total population size can be estimated using:

Total = original number tagged x total recaptured number tagged on recapture

Some examples of how to use this formula:

Total = 50 220 35 = 314.28  so we can say approximately 314

Total = 100  90 12 = 750


Total Population Calculator

To use the calculator, just enter the numbers in the appropriate boxes and press calculate to find the total population size

Original Number tagged:  
Total Recaptured:   
Number tagged on recapture:  



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