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Finance & Irish taxes · Calculator companion · By K Imports

Annual investment IRR and cash-flow value: practical guide

This guide explains how to use the Count.ie annual investment irr and cash-flow value. Solve annual investment return from signed cash flows and assess discounted value. Follow the inputs, method and worked example below, then compare your own scenario.

Guide written .

Open the Annual investment IRR and cash-flow value calculator

What to prepare

  • Have the figures for annual discount rate (%) ready, from a dated document, with the period (annual, monthly or per transaction) that each input expects.
  • Note the date of the transaction, since this model has no year selector and fixed rates may have changed.
  • Separate known facts from assumed rates before relying on the headline result.

Understand the inputs

The calculation method

Discount today and subsequent annual flows; solve a single-sign-change IRR by bisection.

Worked example

Illustrative inputs and their result.

Example inputs

Cash flows: today, year 1, year 2…
-10000, 3000, 4000, 5000
Annual discount rate (%)
5

Calculated example result

Irr Percent
8.8963%
Net Present Value
€804.45

How to interpret the result

Signed flows: investments negative, receipts positive. Distinguish a tax saving, a tax bill, cash received and money remaining: they are not interchangeable. An estimate does not establish eligibility, filing compliance or when a refund will be paid.

Change one input of annual investment irr and cash-flow value at a time and record the result; keep a record of the year, date and assumptions so a change in the result can be explained.

Common mistakes to avoid

  • Do not mix tax years or apply a newly announced measure to an earlier transaction.
  • Avoid counting an allowance, credit, contribution or loss twice.
  • Check exclusions and personal circumstances before relying on the headline result.

Assumptions and sources

Signed flows: investments negative, receipts positive. IRR may be absent or ambiguous; supported root range is -99.99% to 10,000%.

If your case falls outside this scope, use a more suitable calculator or contact us about an unclear method.

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