What Is Net Present Value (NPV)?
Net present value is the difference between the present value of a project's future cash inflows and the initial investment required today. A positive NPV means the project is expected to create value.
NPV is the standard capital budgeting metric because it converts every future rupee into today's terms before comparing it against the upfront cost. This makes projects of different lengths and cash flow shapes directly comparable.
A rupee received five years from now is worth less than a rupee today, since today's rupee can be invested and earn a return in the meantime. NPV discounts every future cash flow to account for exactly that.
How NPV Works: The Time Value of Money
The calculator discounts each year's expected cash flow back to today using the discount rate, then adds every discounted value together. Subtracting the initial investment from that sum gives the NPV.
A higher discount rate shrinks the present value of distant cash flows faster than near-term ones, which is why a project with cash flows loaded toward later years is more sensitive to the discount rate you choose.
NPV Formula: How to Calculate It
NPV = Sum of [Cash Flow(t) / (1 + r)^t] - Initial Investment| Variable | Meaning |
|---|---|
| Cash Flow(t) | Net cash inflow expected in year t |
| r | Discount rate, as a decimal |
| t | Year number of each cash flow |
| Initial Investment | Upfront cash outflow at Year 0 |
Worked example: a small manufacturing unit invests Rs 1,00,000 in a new machine, expecting cash flows of Rs 30,000, Rs 35,000, Rs 40,000, Rs 45,000, and Rs 50,000 over the next 5 years. The owner discounts these at a 10% cost of capital.
| Year | Cash Flow | Computation | Present Value |
|---|---|---|---|
| 0 | -1,00,000 | -1,00,000 | -1,00,000 |
| 1 | 30,000 | 30,000 / (1.10)^1 | 27,273 |
| 2 | 35,000 | 35,000 / (1.10)^2 | 28,926 |
| 3 | 40,000 | 40,000 / (1.10)^3 | 30,053 |
| 4 | 45,000 | 45,000 / (1.10)^4 | 30,736 |
| 5 | 50,000 | 50,000 / (1.10)^5 | 31,046 |
| NPV (sum of present values) | 48,033 | ||
The NPV of approximately Rs 48,033 is positive, so the machine purchase is expected to create value at a 10% cost of capital.
Small rounding differences between a manual calculation and a spreadsheet are normal, and come from how many decimal places each step keeps.
NPV for Equal Annual Cash Flows (Annuity Shortcut)
When every year's cash flow is identical, the annuity formula finds the present value in one step instead of discounting each year separately.
Worked example: a fixed cash inflow of Rs 10,000 a year for 5 years, discounted at 12%, has a present value of Rs 10,000 x [1 - (1.12)^-5] / 0.12, which works out to approximately Rs 36,048.
Against an initial investment of Rs 1,00,000, that gives an NPV of approximately -Rs 63,952, a value-destroying result at this rate and cash flow level. Use the Auto Growth mode above with a 0% growth rate to model this same equal-cash-flow scenario directly in the calculator.
NPV Formula in Excel: Two Methods
Excel's built-in NPV function discounts a range of future cash flows, but does not include the initial investment. Subtract it separately.
| Method | Excel Formula |
|---|---|
| NPV function | =NPV(rate, cash_flow_range) - initial_investment |
| Manual sum | =SUMPRODUCT(cash_flows/(1+rate)^years) - initial_investment |
A common mistake is including the initial investment inside the NPV range, which double-discounts it and understates the result. Keep it out of the range and subtract it once at the end.
How to Choose a Discount Rate for NPV
The discount rate should reflect the return you could reasonably expect from an alternative investment of similar risk, often called the cost of capital.
Indian corporate projects commonly use a weighted average cost of capital (WACC) in the 10% to 15% range, which sits several points above the RBI repo rate to account for business and equity risk.
A personal investment decision can instead use your own required rate of return, such as the return you expect from an equity mutual fund.
NPV vs IRR: What Is the Difference?
NPV tells you the rupee value a project is expected to add. IRR tells you the discount rate at which the project's NPV would equal exactly zero.
Both are useful, but NPV is usually the stronger choice when comparing projects of different sizes, since a high IRR on a small project can add less absolute value than a lower IRR on a much larger one.
NPV vs Payback Period
Payback period tells you how long it takes to recover the initial investment in nominal terms. It ignores both the time value of money and any cash flows that arrive after the payback point.
NPV accounts for both, which makes it the more complete measure when comparing the actual profitability of two projects rather than just how quickly each returns its own capital.
The Discounted Payback figure in the results above uses discounted, not nominal, cash flows, so it already corrects for the time value of money that a plain payback calculation ignores.
Discounted Cash Flow (DCF) and NPV: How They Relate
Discounted cash flow, or DCF, is the general technique of converting a series of future cash flows into their present value. NPV is one specific output of a DCF analysis: the present value of inflows minus the initial investment.
A DCF model can also be used without computing NPV at all, for example to value a company or a bond by discounting its expected future cash flows to a single present-day price.
When to Use NPV
NPV suits capital budgeting decisions: business expansion, machinery purchases, real estate investment, and any case with a large upfront cost followed by several years of expected cash inflows.
Run the same expected return through the CAGR Calculator if you want a single annualised growth rate instead of a rupee value, or the SIP Calculator for regular monthly investment planning rather than a one-time project outlay.
Limitations of NPV
Sensitive to the discount rate: a small change in the assumed rate can flip a project from value-creating to value-destroying, especially over longer horizons.
Depends on cash flow estimates: NPV is only as reliable as the future cash flow projections fed into it, which are themselves uncertain.
Ignores project scale: a large project can show a bigger NPV than a small one purely from size, even if the small project is more efficient per rupee invested.
The Profitability Index shown in the results above (present value of cash flows divided by initial investment) corrects for this. A PI above 1 means the project is value-creating per rupee invested, and it compares across project sizes better than NPV alone.
How to Use This Calculator
- Enter the initial investment: the upfront cash outflow for the project at Year 0.
- Set the discount rate: your cost of capital or required rate of return.
- Choose Manual or Auto Growth: enter each year's cash flow by hand, or set a Year 1 figure and a growth rate.
- Open More Settings for terminal value or inflation: add a terminal value at project end or adjust for inflation.
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Frequently Asked Questions
Disclaimer: All calculations on this page are indicative only. NPV depends entirely on the discount rate and cash flow figures you enter, both of which are estimates about the future. This calculator is for educational and planning purposes only and does not constitute financial or investment advice. Consult a SEBI-registered investment adviser or a qualified finance professional before making capital budgeting decisions.