Frequently asked questions

Do N and I/Y have to use the same period?

Yes. If I/Y is an annual rate, N should count years (or convert to a monthly rate and use months). Mixing a yearly rate with monthly periods without converting will give wrong answers. See formulas for how r and n fit together.

What is the difference between PV and NPV?

Present value usually refers to discounting one amount or a defined stream. Net present value nets all inflows and outflows. Read the short guide for a fuller comparison.

Is this financial advice?

No. This site is for education and quick estimates only. See the disclaimer.

Are my inputs sent to your server?

The calculators run in your browser. See the privacy policy for how the site may handle routine technical data (for example hosting logs).

What discount rate should I use?

Match the rate to risk and period: low-risk cash flows often use lower rates; equities and uncertain projects use higher ones. See the full guide on discount rate explained and try scenarios in the calculator.

How do I use PV for a savings goal?

Set FV to the amount you want, N to your time horizon, and I/Y to the return you assume per period. The lump-sum tool on the home page shows how much you would need today at that assumption—not a guarantee of future returns.