Enter the coral cover, species diversity index, pollution index, and time period into the calculator to determine the Reef Health Index.

Reef Formula

The following formula is used to calculate the health of a coral reef.

RC = (C * S * (1 + P)^T) / ((1 + P)^T - 1)


  • RC is the Reef Health Index C is the coral cover (%) S is the species diversity index P is the pollution index (decimal) T is the time period (years)

To calculate the Reef Health Index, multiply the coral cover by the species diversity index, then raise the result to the power of the time period. Add 1 to the pollution index and raise it to the power of the time period. Divide the first result by the second result, and subtract 1 from the quotient.

What is a Reef?

A reef is a submerged ridge of rock or coral near the surface of the sea, often acting as a barrier or harbor. Coral reefs are formed over thousands of years by the accumulation of coral skeletons and are home to a diverse range of marine life. They play a crucial role in maintaining the health of the ocean ecosystem, including serving as breeding and feeding grounds for many species, protecting coastlines from storms and erosion, and providing benefits to humans such as tourism and fishing opportunities.