Net present value (NPV)
(Rt) Divided by (1+i)t , where t - the time of the cash flow i - the discount rate (the rate of return that could be earned on an investment in the financial markets with similar risk.) Rt - the net cash flow (the amount of cash, inflow minus outflow) at time t (for educational purposes, R0 is commonly placed to the left of the sum to emphasize its role as (minus the) investment).
Metrics & KPIs