Compound interest calculator
See how savings grow with monthly deposits. Tick the DIRT box to take deposit interest retention tax off each interest payment.
| Year | Paid in | Balance |
|---|---|---|
| 1 | €12,400 | €12,629 |
| 2 | €14,800 | €15,312 |
| 3 | €17,200 | €18,049 |
| 4 | €19,600 | €20,841 |
| 5 | €22,000 | €23,690 |
| 6 | €24,400 | €26,597 |
| 7 | €26,800 | €29,563 |
| 8 | €29,200 | €32,589 |
| 9 | €31,600 | €35,676 |
| 10 | €34,000 | €38,826 |
How it works
Each month your deposit is added and a month's interest is paid on the whole balance. Over the years, interest earned on earlier interest becomes a large part of the total.
DIRT on deposit interest
Banks and credit unions deduct Deposit Interest Retention Tax at 33% from the interest they pay Irish residents. The tax is taken at source, so you usually have nothing more to pay. At a 3% rate before DIRT, your real return is 2.01%.
People aged 65 or over whose income is below the age exemption limit, and people who are permanently incapacitated, can apply to Revenue to have DIRT refunded or not deducted.
Examples over 10 years
| Start | Monthly | Rate | Before DIRT | After DIRT |
|---|---|---|---|---|
| €1,000 | €100 | 2% | €14,515 | €13,991 |
| €10,000 | €200 | 3% | €41,512 | €38,826 |
| €20,000 | €0 | 3.5% | €28,367 | €25,280 |
| €0 | €500 | 2.5% | €68,228 | €65,359 |
Inflation reduces what the final balance will buy, so compare your after-DIRT rate with the Consumer Price Index. Paying off a credit card or personal loan at a higher rate usually beats saving the same money.
State savings
Interest on An Post State Savings products, such as Savings Certificates and Savings Bonds, is paid free of DIRT. Their rates are fixed for a term, so enter the rate quoted and untick DIRT to compare them fairly with a bank deposit.
Common questions
What is €10,000 at 3% for 10 years in Ireland?
About €13,494 before tax, or €12,224 after DIRT at 33%, with monthly compounding.
Is DIRT charged on credit union dividends?
Yes. Credit unions deduct DIRT from deposit interest and from share dividends before paying you.
Does the calculator include inflation?
No. It shows the money balance. To see real growth, subtract the inflation rate from your after-DIRT rate.
What is AER?
The Annual Equivalent Rate shows what you would earn in a year with compounding included, so you can compare accounts that pay interest at different intervals.
Sources
Checked 28 September 2026. OneCalcs is independent and not affiliated with Revenue, the Department of Social Protection, Citizens Information or any other government body.