• The population density of England is around 433 people per km2. 
  •  If the Republic of Ireland had that population density, around 30 million people would live there.
  • However, Ireland can also refer to the island of Ireland – which would indeed have a population of around 35 million people.

On 25 March, Irish comedian Tadhg Hickey claimed on social media:

“Had we English levels of density we’d have a population of 35 million.”

Mr Hickey’s comment was in response to social media comments complaining about immigrants and stating that “Ireland is full”.

If the Republic of Ireland had the same population density as England, its population would be around 30.2 million people – lower than in the claim..

However, Ireland can also refer to the island of Ireland. If it had a similar population density to England, its population would be around 36.1 million people – which is indeed approximately 35 million.

With that caveat, the claim is accurate.

Population density

The population density of a given place is the number of people who live in that place per unit area of land. Put more simply, it is the number of people in a space, relative to the size of that space.

Working out population density requires a simple calculation – total population divided by the total area of the land. And, turning the equation around, population = area x population density.

Comparing places

Latest figures from the Office of National Statistics (ONS), based on data from the 2021 Census, put the population density of England at around 433.5 persons per square kilometre.

For comparison, the population density of Ireland was 70 persons per square kilometre using 2016 Census figures from the Central Statistics Office (CSO). Preliminary figures from the 2022 Census show a rise in population – from 4.75 million in 2016 to around 5.1 million now – suggesting that the current population density is closer to 75 persons per square kilometre.

Northern Ireland’s population density is higher than the rest of Ireland, at 140.2 persons per square kilometre (population of 1.9 million).

Claim

Data from the CSO shows that Ireland’s total land area is around 69,700 square kilometres.

If its population density was the same as England – 433.5 persons per square kilometre – its population would be (69700 x 433.5) = 30.2 million people.

This is short of the claimed 35 million. However, “Ireland” can refer to the Republic of Ireland or the geographic island of Ireland.

Including NI

According to the Northern Ireland Statistics and Research Agency (NISRA), the land area of Northern Ireland is around 13,547 km2.

So if the island of Ireland had a similar population density to England, its population would be ((69700+13547) x 433.5) = 36.1 million people.

It is reasonable to round that down to 35 million people so, bearing all this in mind, Mr Hickey’s claim is accurate.