The short answer
- Pick your target: 1,825 days over 9 years for most adults, or 1,095 over 5 for spouses and civil partners of Irish citizens, plus a day for each 29 February.
- Start at the start date: your oldest row begins on the calculator’s start date, not the day your first stamp began.
- Oldest first: enter Stamp 1G as 1, leave out Stamp 2, and don’t repeat days two stamps share.
- Check its answer: it doesn’t add 29 February 2024, and it counts anything you type, even from before the start date.
Prepare your rows
Calculator helper
Enter your permissions with the dates on your IRP cards. You’ll get the rows to type into ISD’s calculator, and a check of its answer.
| Start | End | Stamp | Days |
|---|
Worked out in your browser: nothing you enter is sent to us or saved. It mirrors how ISD’s calculator worked when we tested it on 3 October 2026. Neither replaces ISD’s own assessment, and neither checks absences.
Step by step
- Open the calculator from ISD’s naturalisation residency calculator page. It’s for non-EU, non-EEA and non-Swiss nationals.
- Enter your application date. It has to be before your current stamp expires: if your card expires first, renew before you apply.
- Choose your target: residence in the State (1,825 or 1,826 days over 9 years), or marriage or civil partnership with an Irish citizen (1,095 or 1,096 over 5 years).
- Note the start date it shows: your application date, 9 years earlier (or 5).
- Enter your oldest stamp from the start date, including the part of it after that date. Then every other stamp, oldest to newest, up to 20.
- Choose the stamp type for each row. Use 1 for Stamp 1G. Stamp 2 and 2A count for nothing.
- Read the two results: whether the year before you apply is unbroken, and whether you have 3 or 5 years.
Two ways its answer can be wrong
We tested ISD’s calculator on 3 October 2026 and read its code. Two things to watch:
- Leap days after 2020. ISD’s guidelines add a day for each 29 February, but the calculator’s list of leap days stops at 2020. If your window includes 29 February 2024 (or 2028), you need one more day than the calculator asks for. Leave a few days’ margin.
- Stamps before the start date. The calculator doesn’t trim them. In our test, a stamp from 2012 to 2015 typed in for a June 2025 application was counted, and the result said “Has 5 Years Residency” when the real total was 366 days. Begin your oldest row on the start date.
The helper above gives you the rows already trimmed, and counts with every leap day.
What the results mean
| Result | What it means |
|---|---|
| Residency in year prior to application ok | Your stamps run unbroken for at least a year back from your application date |
| Year prior to application not continuous | A gap in the last year, or your stamp ends before your application date |
| Has 5 (or 3) Years Residency | Your counted days meet the target, as the calculator works it out |
| Less than 5 (or 3) Years Residency, X days short | Wait at least that many days: ISD says not to sign the statutory declaration or apply until then |
The result is a guide, not a decision: ISD assesses your residence when you apply. If you don’t meet the requirements, the calculator’s disclaimer says the application may be deemed ineligible, and you’d have to apply again.
What the calculator doesn’t check
- Absences: the 70-day rule isn’t in it.
- Stamp 0: ISD’s guide says it counts, but it isn’t in the calculator’s list of stamps. Ask ISD how to show it.
- Northern Ireland: on the spouse route, time on the island of Ireland counts, but the calculator only takes Irish stamps.
- Evidence: you still need 150 points of documents for each year.
For when you could apply in the future, use the citizenship clock or the 5-in-9 window explorer.
Common mix-ups
Common questions
Who should use ISD's residency calculator?
Non-EU, non-EEA and non-Swiss nationals applying on residence, or as the spouse or civil partner of an Irish citizen. UK, EU, EEA and Swiss nationals don't use it, and ISD says it doesn't work for refugees.
What is the start date?
The day and month of your application date, 9 years earlier (or 5 years for the spouse route). Your oldest stamp row should begin on that date, even if the stamp itself started earlier.
How do I enter Stamp 1G?
As Stamp 1. ISD's calculator has no 1G option, and ISD says to enter it as Stamp 1.
Should I enter Stamp 2?
You can, but it counts as 0 days and is ignored for the year before you apply. Leaving it out keeps the list simpler.
What if two stamps overlap?
ISD says to use the one with the longest duration or latest expiry. Enter stamps oldest to newest: the calculator trims each one against the row before it.
The calculator says I have 5 years. Can I apply?
Check the leap days and the start date first: the calculator can say yes a day early if your window includes 29 February 2024, or if you entered a stamp from before the start date. It also doesn't check absences, and its result isn't a decision: ISD assesses your residence when you apply.
What does 'year prior to application not continuous' mean?
There's a break in your permissions in the 12 months before your application date, or your latest stamp ends before it. The final year must be unbroken, so renew on time and check your dates.
Sources
All sources checked on 3 Oct 2026.
- Naturalisation residency calculator and guidelinesImmigration Service Delivery
- Becoming an Irish citizen guide (reckonable residence)Immigration Service Delivery
- Irish Nationality and Citizenship Act 1956, sections 15, 15A and 16A (revised)Law Reform Commission