Engineering Economics Calculators
NPV, IRR, LCOE, and the finance behind engineering decisions.
- Net Present Value (Uniform Cash Flow)Discount an initial cost plus a level annual cash flow to present value and get the NPV of the project.NPV = −C₀ + A·(P/A, i, n) + S·(P/F, i, n) , (P/A) = [(1+i)ⁿ − 1] / [i(1+i)ⁿ]
- Simple Payback PeriodHow many years an energy or capital retrofit takes to pay back its first cost from annual savings.Payback = (Initial cost − Salvage) ÷ (Annual savings − Recurring cost)
- Levelized Cost of Electricity (LCOE)Compare generation options on one number — annualized capital plus O&M and fuel, per MWh delivered.LCOE = (CapEx·CRF + FOM)·1000 / (8760·CF) + VOM + Fuel , CRF = r(1+r)ⁿ / [(1+r)ⁿ − 1]
- 1-Way Sensitivity Range (Tornado)Swing one input between its low and high bound and see how far the result moves — the bar length of a tornado diagram.Output = Base + Sens·(Input − Nom) , Swing = |Output(hi) − Output(lo)|
- Loan Amortization PaymentLevel periodic payment, total interest, and payoff for a fully amortized loan.A = P · [ i(1+i)ⁿ ] / [ (1+i)ⁿ − 1 ] , i = r/m , n = years·m