NPV Calculator
Annual Cash Flows
What Is NPV (Net Present Value)?
Net Present Value (NPV) is the difference between the present value of all future cash inflows and the initial investment cost. A positive NPV means the investment generates more value than it costs when adjusted for the time value of money — it's a good investment. A negative NPV means the investment destroys value and should be rejected.
The core insight is that money today is worth more than the same money in the future. A dollar received in 5 years is worth less than a dollar today because today's dollar can be invested and grow. The discount rate (also called the required return or hurdle rate) captures this — it's the minimum return you need to accept the risk of the investment.
Formula: NPV = −Initial Investment + Σ [Cash Flow(t) / (1 + r)^t] where r is the discount rate and t is the year number.
How to Use This NPV Calculator
- Enter the Initial Investment — the amount spent today (e.g., $100,000 for equipment).
- Enter the Discount Rate — your required return rate or cost of capital (e.g., 10%).
- Enter the expected Annual Cash Flows for each year. Add more years with the "+ Add Year" button.
- Click Calculate NPV to see NPV, total present value, ROI, and a year-by-year table.
- Positive NPV → accept the investment. Negative NPV → reject or revise assumptions.
Worked Example: Equipment Purchase Decision
A company considers buying a machine for $100,000. Expected annual cash flows over 5 years at a 10% discount rate:
| Year | Cash Flow | PV Factor (10%) | Present Value |
|---|---|---|---|
| 1 | $30,000 | 0.909 | $27,270 |
| 2 | $30,000 | 0.826 | $24,780 |
| 3 | $25,000 | 0.751 | $18,775 |
| 4 | $25,000 | 0.683 | $17,075 |
| 5 | $20,000 | 0.621 | $12,420 |
| Total PV | $130,000 | $100,320 |
NPV = $100,320 − $100,000 = +$320. Barely positive — accept if confident in estimates, but this is a marginal investment.
Choosing the Right Discount Rate
- Weighted Average Cost of Capital (WACC): The most common corporate discount rate — blends the cost of debt and equity. Typically 8–12% for established businesses.
- Risk-free rate + risk premium: Start with the 10-year Treasury yield (~4–5%) and add a risk premium for the specific investment risk.
- Opportunity cost: If you could earn 7% in an alternative investment, use 7% as your discount rate — the project must beat that return to be worthwhile.
- Higher rate = stricter standard: Using 15% instead of 10% makes NPV lower, reflecting higher return requirements for riskier projects.
- Real vs. nominal: If cash flows are in nominal (current) dollars, use a nominal discount rate. If adjusted for inflation, use a real rate.
NPV vs. IRR vs. Payback Period
| Metric | What It Tells You | Limitation |
|---|---|---|
| NPV | Dollar value created or destroyed | Requires accurate discount rate estimate |
| IRR | Actual return rate of the investment | Can give misleading results with non-standard cash flows |
| Payback Period | How many years to recover investment | Ignores cash flows after payback, ignores time value |
| ROI | Total percentage return | Ignores timing of cash flows |
NPV is generally considered the most theoretically sound investment criterion. Use it alongside IRR and payback period for a complete picture.
Frequently Asked Questions About NPV
What does a positive NPV mean?
A positive NPV means the investment generates more value than its cost when accounting for the time value of money. Accept the project — it creates value for shareholders.
What does a negative NPV mean?
A negative NPV means the investment returns less than your required rate of return. The investment destroys value — reject it unless there are strategic non-financial benefits.
What discount rate should I use for NPV?
Use your cost of capital (WACC) for corporate investments, your opportunity cost for personal investments, or a risk-adjusted rate that reflects the project's specific risk level. Common rates range from 6–15%.
How does the discount rate affect NPV?
Higher discount rates reduce NPV — future cash flows are worth less when discounted at a higher rate. As discount rate increases, NPV decreases. The rate at which NPV equals exactly zero is the Internal Rate of Return (IRR).
What is the difference between NPV and IRR?
NPV gives you the dollar value of the investment (in today's money). IRR gives you the percentage return rate. For single investments, both methods reach the same accept/reject decision. For comparing multiple projects, NPV is more reliable.
Can NPV be used for personal financial decisions?
Yes. NPV works for evaluating solar panels, rental properties, education degrees, car purchases, or any decision with upfront costs and future benefits. Use your expected investment return rate as the discount rate.
What is a good NPV?
Any positive NPV is technically "good." Higher positive NPV means more value created. When comparing multiple projects of similar scale, choose the one with the highest NPV.
How does NPV account for the time value of money?
NPV discounts each future cash flow by (1+r)^t, where r is the discount rate and t is the number of years. Cash flow received in year 5 is divided by (1+r)^5, making it worth less than the same amount received today.