Species Richness (Margalef & Menhinick)
Calculate Margalef and Menhinick species richness indices from the number of species and individuals, free online.
About this calculator
Richness indices correct the raw species count S for sample size N. Margalef: (S − 1) ÷ ln N. Menhinick: S ÷ √N. Higher values mean more species per individual sampled; compare only samples collected with similar effort.