Biodiversity Credit Calculator

This calculator sizes a farm's pollinator/biodiversity habitat program and puts a rough dollar figure on it. Start by setting aside your habitat target percentage of total farm acreage (the Xerces Society's NRCS-partnered pollinator habitat assessment guidance lists 3-5% of farm acreage in natural or semi-natural habitat as a recognized benchmark) and splitting it across a number of patches — the calculator divides total habitat acres evenly across however many patches you specify. From there it builds a 0-100 biodiversity quality score from four weighted components, each worth up to 25 points: average patch size (bigger patches score higher, capping out around 2.5+ acres), the percentage of native plant species in your seed mix, how many months of the growing season have continuous bloom, and a connectivity bonus that rewards spreading habitat across more patches: 3 points per patch (capped at 25) once each patch clears a 0.25-acre minimum, or half that rate — 1.5 points per patch, still capped at 25 — for patches below it, since sub-quarter-acre fragments still add some pollinator value, just at a reduced rate rather than zero.

Estimated pollinator species supported uses a species-area relationship borrowed from island biogeography (species count scales with habitat area raised to the 0.25 power), scaled further by native plant percentage. Pollination service coverage assumes each acre of habitat can effectively service about 18 acres of adjacent cropland via foraging pollinators, capped at your total farm size. On the financial side, expect a one-time seed/establishment cost plus a flat $75/acre annual maintenance estimate, and a projected credit revenue that simply multiplies acres by score (as a fraction of 1 credit/acre at a perfect 100) by your assumed credit price — voluntary biodiversity credit markets are thin and immature, so treat this revenue figure as a rough estimate rather than a guaranteed offtake price.