The 75-plus age group makes up the largest group of people in the UK who live alone at nearly one fifth of the total.
Birmingham has the greatest number of people living alone in the country, according to the EuroDirect Singles Report.
The 60 to 74 age group makes up 19% of those who live by themselves.
People in the 35 to 39 age group account for 10% of single dwellers, while the 40 to 44 bracket makes up 9.5% of the total.
In the 75-plus age group the proportion of single women living alone outnumbers men by 36%, according to EuroDirect.
Belfast comes second in its list of areas with the most people living alone.
Glasgow has the third highest number of single dwellers - and 40,000 more women living alone than men.
Reading is named the top postcode area for single men living alone, with 10,711 more of them than single women.
EuroDirect managing director John Dobson said the Singles Report had been created primarily to help marketers target their campaigns.
"By identifying the post areas where the UK's singles living alone are located and the areas with the greatest amount of disparity between the genders, this report might be able to help more than just marketers find who people want to connect with," he said.
EuroDirect is a marketing supply company. Its database identified 9,899,196 people living alone in the UK.
Those figures came from its list of some 43 million people in the UK which is compiled from the edited electoral roll, customer questionnaires, shareholders lists and other sources.
The company defines "single" people as those who are unmarried and who live alone.
According to EuroDirect, the top 10 UK postcode areas for single people living alone in the UK are as follows:
1. B Birmingham - 281,742
2. BT Belfast - 239,034
3. G Glasgow - 221,564
4. S Sheffield - 215,965
5. NE Newcastle Upon Tyne - 204,470
6. M Manchester - 199,490
7. NG Nottingham - 177,235
8. SE London - 173,506
9. SW London - 162,931
10. L Liverpool - 155,717