Biodiversity is primarily measured through objective means, focusing on species richness (the number of species) and species evenness (their relative abundance) within a specific geographic area and time. The most widely used metrics for this purpose are the Shannon-Weaver diversity index and the Simpson's diversity index, with Shannon's often favored for its comprehensive inclusion of species richness.

While other types like ecological, morphological, and genetic diversity exist, taxonomic diversity—quantifying species, genera, or families—is the most commonly assessed. Newer indices, such as the Mean Species Abundance Index (MSA) and the Biodiversity Intactness Index (BII), track population size trends and measure local biodiversity's response to human pressures like land use change. These various measurements are vital for conservation biologists, guiding efforts to preserve genetic variety and ensure environmental sustainability for future generations.