Irish Calculators
Loans & mortgages

Net Present Value Calculator for Dated Cash Flows

Enter the dates and signed amounts of project cash flows to find their value at one common date. The discount rate and any tax or risk adjustments must be reflected in your inputs.

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Your numbers

Each line: YYYY-MM-DD, signed amount. Outflows negative, inflows positive. Enter dates on or after the valuation date.
Your figures stay on this device.

How the calculation works

Dated net present value brings all project receipts and payments to one valuation date. It preserves their signs and timing, so a future receipt is not treated as equally valuable to cash available immediately.

NPV = sum(cash flow / (1 + effective annual discount rate)^(actual days from valuation / 365)).

  1. Measure the time to each flow

    The tool counts actual UTC calendar days from valuation and divides by 365. Leap days are counted, but the denominator remains 365.

  2. Discount each signed amount

    Divide the amount by one plus the annual rate raised to that fractional-year interval. The table shows the resulting present value for each row.

  3. Add the present values

    Summing positive and negative discounted amounts gives NPV. The separate undiscounted sum helps distinguish simple cash surplus from a return after allowing for time.

Worked example: One-year discounted break-even

Sample inputs demonstrate the method. They are not a forecast or product offer.

The example pays €1,000 on 1 January 2026 and receives €1,100 on 1 January 2027. Discounting the receipt for 365 days at 10% gives €1,000. It offsets the initial negative €1,000, so NPV is zero although undiscounted cash surplus is €100.

Effective annual discount rate
10
Valuation date
2026-01-01
Dated cash flows
2026-01-01,-1000 2027-01-01,1100

Expected result

Net present value
€0.00
Undiscounted net cash flow
€100.00
Worked example: Zero discount sums signed cash flows

Sample inputs demonstrate the method. They are not a forecast or product offer.

Effective annual discount rate
0
Valuation date
2026-01-01
Dated cash flows
2026-01-01,-1000 2026-06-01,400 2027-01-01,800

Expected result

Net present value
€200.00
Undiscounted net cash flow
€200.00

Understanding your result

A positive NPV means the entered receipts exceed the entered outlays at the chosen required return. It does not confirm that the forecast receipts will occur.

Unlike a restricted IRR solver, this sum can accommodate later investments and multiple changes of sign. Changing the discount rate is a useful sensitivity check rather than a new prediction.

Questions you might have

Does a positive NPV guarantee a profitable investment?

No. It means the entered cash flows exceed the required return at your chosen rate; the forecasts may differ from reality.

Choosing the right inputs

Dated cash flows
Enter chronological rows containing YYYY-MM-DD and a signed amount. Outlays are negative and receipts positive. Include the initial investment explicitly; a heading or thousands separator is not accepted.
Valuation date
Choose a date on or before every cash flow. A flow on this date has no discounting, even if it is the initial investment.
Effective annual discount rate
Enter an effective annual discount percentage consistent with the cash flows. Match nominal forecasts with a nominal rate, or real purchasing-power forecasts with a real rate.

Common mistakes to avoid

  • Do not omit the initial outlay or put it in as a positive receipt.
  • An exact calendar year containing a leap day spans 366/365 model years under this convention.

Assumptions to check

  • Cash flows and discount rate are scenarios. Taxes and risk adjustments are included only if you enter them.

Sources and method

Read our calculation and testing approach.