An Excel based macro-driven project calculator from The Nature Conservancy. The purpose of the calculator is to allow the user to estimate the potential carbon tonnage sequestered from a specific ecosystem project area and the associated costs of creating and maintaining the project. The calculator is intended to produce "first cut" estimates for a forty-year project feasibility study. Outputs include: carbon sequestered annually and over project term, project investment required and capital reserve required to offset market volatility, etc.