| Name of index | Expression | Description |
| Renewable ratio (R ) | - | Local/free renewable resource. R is a renewability factor indicating the percentage of renewable emergy locally available used by the system |
| Nonrenewable sources (N ) | - | Local/free non-renewable resource |
| Economy feedback (F) | - | Feedback from the economy or purchased resources |
| Energy yield (E) | - | Energy yield of each product |
| Total emergy output (Y) | Y = R + N + F | Total emergy |
| Transformity or energy transformation (Tr) | Tr = (R + N) + F/E | Emergy input per unit of available energy output (Emjoule/joule). Tr is the inverse value of the system efficiency. |
| Materials (M) | M = Mr + Mn | It includes the sum of renewable materials and energy (Mr) and nonrenewable materials and energy (Mn). |
| Services (S) | S = Sr + Sn + Ss | It includes the sum of renewable services (Sr), nonrenewable services (Sn) and externalities (Ss) |
| Emergy yield ratio (EYR) | EYR = Y/F | Total emergy (Y) divided by the sum of the feedback emergy of non-renewable inputs from economy (M + S) |
| Emergy investiment ratio (EIR) | EIR = F/(N + R) | It is the relation between flows of imported emergy (F) from the economy divided by the local inputs from the environment |
| Environmental loading ratio (ELR) | ELR = (N + F)/R | Ratio of total nonrenewable emergy (N + F) divided by the total renewable emergy (R) for a given productive process |
| Emergy sustainable index (ESI) | ESI = EYR/ELR | Ratio of EYR divided by ELR. ESI reflects the capacity of the grassland to provide services with a minimum environmental pressure and a maximum economic profit |
| Emergy exchange ratio (EER) | EER = Y/[($) × (sej/$)] | Ratio of emergy of the product and emergy received in a trade or purchase |