Use Effective Population Size when you need to compute the sex-ratio effective population size ne = (4 * males * females) / (males + females). Enter Males and Females using the definitions and units below so the result can be reproduced.

Males

An integer count or setting greater than or equal to 1.

Females

An integer count or setting greater than or equal to 1.

The published tool contract uses this rule: Compute the sex-ratio effective population size ne = (4 * males * females) / (males + females).^[1]

Effective size

The calculated effective size.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.

Retain the original Males and Females values and their units alongside the result. Ecological Doubling Time is useful when you instead need to compute the doubling time of a population growing exponentially. Exponential Growth provides another view by helping you project a population with continuous exponential growth.

• Ecological Doubling Time

  Compute the doubling time of a population growing exponentially.

• Exponential Growth

  Project a population with continuous exponential growth.

• Lincoln Petersen Estimator

  Estimate population size from two capture sessions with the Lincoln Petersen index.