Net Present Value: The Formula That Clarifies Every Financial Decision
Calculate NPV for any scenario with our [Net Present Value Calculator](/calculators/finance/net-present-value-calculator).
What Is Net Present Value?
NPV converts a stream of future cash flows into a single present-day dollar amount, accounting for the time value of money (a dollar today is worth more than a dollar in the future because it can be invested).
NPV Formula: Sum of [Cash Flow / (1 + Discount Rate)^Year] minus Initial Investment
Positive NPV = good investment (worth more than it costs in today dollars)
Negative NPV = bad investment (costs more than it returns in today dollars)
Simple Example: Rental Property
Purchase: $300,000 down payment
Annual net cash flow: $12,000/year (after all expenses)
Sale in year 10 for: $450,000 net
Discount rate: 8% (your alternative investment return)
| Year | Cash Flow | Present Value |
|---|---|---|
| 1-10 | $12,000/year | $80,520 |
| Year 10 (sale) | $450,000 | $208,470 |
| Total PV | | $288,990 |
| Initial investment | | -$300,000 |
| NPV | | -$11,010 |
NPV is negative — meaning at this price and rent, the stock market at 8% return beats this rental property.
NPV in Common Decisions
Job offer with deferred compensation:
Company A: $100k salary now.
Company B: $85k salary + $200k in stock vesting over 4 years.
NPV comparison tells you the real value of Company B's offer in today's dollars (discounted for risk and time).
Buy vs lease equipment:
Buy: $50,000 upfront, zero payments, asset at end.
Lease: $1,200/month for 4 years, return at end.
NPV shows which costs less in today dollars.
Choosing Your Discount Rate
The discount rate is your personal opportunity cost — what you would otherwise earn:
- Very conservative investor: 5-6% (high-grade bonds)
- Moderate investor: 7-8% (balanced portfolio)
- Aggressive investor: 9-10% (equity-heavy)
- Business decisions: often 10-15% (cost of capital)
NPV vs ROI vs CAGR
| Metric | Best For |
|---|---|
| NPV | Comparing options with different timing and amounts |
| ROI | Quick percentage return on a single investment |
| CAGR | Annualizing returns for consistent comparison |
Use NPV when cash flows are irregular or multi-year. Use ROI for simple one-period comparisons.
Related Tools
- [ROI Calculator](/calculators/finance/roi-calculator) — Simple return percentage
- [Rental Property Investment Calculator](/calculators/finance/rental-property-investment-calculator) — Full property NPV analysis
- [Opportunity Cost Calculator](/calculators/finance/opportunity-cost-calculator) — Time value of spending decisions