How much your savings grow with a starting amount, a monthly deposit and compound interest, after DIRT and in today's money.
This is an estimate for general information, based on the rates and rules described on this page. It is not financial, tax or legal advice and does not take account of your full circumstances. Check your own position with Revenue or a qualified financial adviser before making a decision. Terms of use.
How compound interest is calculated
With monthly compounding, each month the balance earns one twelfth of the yearly rate, then the monthly deposit is added. With yearly compounding, interest is added once a year: the balance at the start of the year earns the full rate, and each deposit earns interest for the months it was in the account. When DIRT is on, 33% of each interest payment is taken as it is added, so only the rest goes on to earn interest.
Example. You start with €5,000 and add €200 a month for 10 years at 3%, with interest added monthly. You pay in €29,000. Before tax, the balance grows to €34,695.05, with €5,695.05 of interest. With DIRT at 33%, the balance is €32,669.61. With 2% inflation, that is worth about €26,800 in today's money.
What this calculator assumes
The interest rate stays the same for the whole time. Most savings rates are variable.
Deposits are made at the end of each month and nothing is withdrawn.
DIRT is taken from each interest payment as it is added. The rate is the one in force today.
Fees, account limits and changes to tax rates are not included.
Sources
Rates last checked 10 October 2026. Every figure is listed on rates and sources.
Figures marked as announced come from Budget 2027 and are not law until the Finance Act 2026 is signed.
Compound interest is interest earned on interest. Each time interest is added to the account, the next interest payment is worked out on the larger balance. €10,000 at 3% a year earns €300 in the first year, but after 10 years of compounding the balance is €13,439.16, not €13,000.
Is DIRT taken from savings interest in Ireland?
Yes. Deposit Interest Retention Tax of 33% is taken by the bank or credit union from interest on deposit accounts before it is paid to you. It is a final tax for most people, so there is usually nothing more to pay. People aged 65 or over, or permanently incapacitated, whose income is below the income tax exemption limit can claim it back. State Savings products from An Post are tax free.
Does monthly or annual compounding make a big difference?
A small one. Monthly compounding adds interest twelve times a year, so the interest starts earning interest sooner. At 3% the difference over 10 years is a few euro per thousand saved. The rate itself matters far more.
What is the difference between AER and the interest rate?
The AER (annual equivalent rate) shows what the interest would come to over a year once compounding is included, before DIRT. If an account quotes an AER, enter it with annual compounding to match it.
What does the inflation figure do?
It shows the final balance in today's money. With 2% inflation, €10,000 in 10 years buys about what €8,200 buys today. If your savings rate after DIRT is below inflation, the real value of your savings falls even though the balance grows.
Can I use this for an investment fund or ETF?
Only roughly. Funds and ETFs do not grow at a steady rate, and they are taxed under exit tax with a deemed disposal every 8 years, not DIRT. The ETF exit tax calculator models that tax.
