📈 Compound Interest Calculator
What will my savings actually grow to?
Most compound interest calculators are wrong for an Irish saver in two ways. They ignore DIRT, which takes a third of the interest before it reaches the account, and they give a number for fifteen years’ time without saying what it will buy. This does both, and shows the year the interest starts outgrowing what you are putting in.
Figures reviewed September 2026. Free, no signup, nothing stored on our servers.
What this means
The final balance is what should actually be in the account, after tax. The gross figure above it is what a rate-based calculator would have told you, and the difference between them is DIRT — deducted at source, so there is nothing to file and no way to avoid it on a bank or credit union deposit.
The effective rate after tax is the number worth comparing between products. A bank quoting 3% is offering roughly 2% once DIRT is taken. A State Savings product quoting a lower headline figure may well be paying more, because its return is exempt.
The figure in today’s money exists because the nominal balance answers the wrong question. Over a long enough horizon, a deposit account paying less than inflation loses purchasing power every year while the balance goes up — which looks like saving and is not.
What affects the result
- The rate, which does more than anything else over a long term and is yours to shop for.
- Whether DIRT applies. State Savings products are exempt; bank, credit union and An Post deposit accounts pay it.
- How often interest is credited. Monthly compounding beats annual at the same rate, though most Irish deposit accounts credit once a year.
- The monthly contribution, which dominates the first several years — far more than the rate does.
- Time. The interest only outgrows the contributions after a long run, which is the whole argument for starting early.
- Inflation, which decides what the balance is actually worth.
What will my savings actually grow to?
Compare on the net rate
The only honest comparison between two savings products is what each leaves you with after tax. Reduce every taxable rate by DIRT before putting it beside a State Savings return, and check whether a headline rate is a regular-saver rate that applies to a few hundred euro a month and reverts afterwards.
What this money is for
Short-term money belongs where it is accessible — the emergency fund calculator covers how much that should be. Money you will not need for years faces a different question, and pension relief at your marginal rate beats a deposit account on tax alone.
Before you save anything
If there is expensive debt in the house, clearing it outranks saving — the payoff calculator shows what it is actually costing. And the savings comparison covers where an Irish deposit should sit once you know how much of it there will be.
Important assumptions
Every figure on this page rests on these. Where one does not match your situation, the answer moves — sometimes a great deal.
- The rate you enter is the gross annual rate, as an institution quotes it. Nothing here assumes what any Irish account pays.
- DIRT is applied at the current rate when interest is credited, once a year. It is deducted at source in reality, so the net figure is what reaches the account.
- Contributions are added at the start of each month, the way a standing order works.
- The rate is held constant for the whole term. Real deposit rates move, and a fixed-term product ends.
- The inflation adjustment uses the rate you set, and defaults to zero. Assuming one would be inventing it.
- Regular-saver accounts usually cap the monthly amount and the term, and revert to a much lower rate afterwards. This does not model that revert — check the product terms.
Official sources
Where this tool applies a published rule, this is where the rule comes from. Check the source before acting on anything that matters.
- Revenue — Deposit Interest Retention Tax
The DIRT rate, how it is deducted, and the exemptions for people over 65 and people who are permanently incapacitated.
- State Savings (NTMA)
The products that are exempt from DIRT — savings certificates, savings bonds, instalment savings and Prize Bonds — and their current returns.
- CCPC — savings account comparison
The statutory consumer body’s independent comparison of Irish deposit rates.
- Deposit Guarantee Scheme
The protection limit per person per institution, should a bank or credit union fail.
Common questions
How much tax do I pay on savings interest in Ireland?
Deposit Interest Retention Tax is deducted at source by the bank or credit union, so the interest you see credited is already net. There is nothing to file. People aged 65 or over whose income is below the exemption limits, and people who are permanently incapacitated, may be able to receive interest without DIRT deducted or reclaim it — Revenue sets the conditions.
Are State Savings tax free?
Yes. Savings certificates, savings bonds, instalment savings and Prize Bond winnings are exempt from DIRT. That is why a State Savings return cannot be compared directly with a bank’s headline rate — the bank rate has to be reduced by DIRT first to be comparable.
Is my money safe in an Irish bank?
Eligible deposits are protected up to €100,000 per person per institution under the Deposit Guarantee Scheme. The limit is per institution, not per account, so splitting large balances across institutions is how the protection is extended.
Should I save or pay off debt first?
Almost always pay off the debt, where the debt costs more than the savings earn. A deposit paying 3% gross is paying about 2% after DIRT; a credit card charging 20% costs ten times that. Clearing it is a guaranteed, tax-free return at the card’s rate.
Is a savings account a good place for long-term money?
For an emergency fund, yes — accessibility is the point. For money you will not need for a decade, a deposit account paying less than inflation loses purchasing power every year, which is exactly what the "in today’s money" figure here is for.
What to check next
Where should my savings actually sit?
Compare Irish deposit rates and see what DIRT leaves you with.
Savings ComparisonNewHow much should I keep in reserve?
A suggested range based on your essential outgoings, job security and dependants.
Emergency Fund CalculatorWhat does a pension contribution really cost me?
Age-banded relief limits and the net cost of contributing at Irish tax rates.
Pension Tax ReliefNewWhen will this debt actually be gone?
Payoff date, total interest, and what an extra €50 a month would change.
Debt Payoff CalculatorNext steps across CheckIreland
Picked for what you just worked out — not a list of everything we make.
- How much should be accessible?A projection is only useful once you know which part of the money can be tied up.
- Relief beats interestDeposit interest is taxed at 33%; pension contributions get relief at up to 40%. On long money that gap dwarfs any rate.
- Debt first, if there is anyClearing a card charging 20% is a guaranteed tax-free return no deposit account can match.
CheckIreland is independent and is not affiliated with the Irish Government or any public body. This tool is general information built on published rules and typical costs — it is not financial, tax or legal advice, and it does not account for your individual circumstances. Confirm anything that matters with the relevant body or a qualified adviser before acting on it.