ALIS-Light public report · Office for National Statistics
Fertility across birth cohorts in England and Wales
ONS data show that completed family size was lower for women born in 1979 than for selected earlier generations, while childbirth occurred later. The principal population projection indicates still smaller average family sizes for younger female cohorts, but those projected values are scenarios rather than forecasts.
Official bulletin and dataset checked
Source and coverage
- Institution
- Office for National Statistics (ONS)
- Release
- Fertility for those born in different years, England and Wales: 2024
- Publication date
- 10 June 2026
- Observed data period
- Birth registrations and population estimates through 2024
- Female cohort coverage
- Observed cumulative data for birth cohorts 1920–2009; observed and projected completed-family-size data for cohorts 1920–2034
- Male cohort coverage
- Cumulative data for birth cohorts 1949–2009; complete cohort histories for men born 1949–1959
What the observed data show
Women born in 1979 are the latest female cohort for which ONS reports a completed family size based entirely on observed data. Their average was 1.95 live-born children, compared with 2.05 for women born in 1953 and 2.12 for women born in 1925.
The change was also about timing. The 1979 cohort averaged one child per woman by age 31, compared with age 27 for the 1953 cohort and age 28 for the 1925 cohort.
The proportion of women born in 1979 who had no children was 15.7%. ONS reports that this was close to the corresponding shares for the selected mother and grandmother cohorts, so the smaller average family size cannot be described simply as a large rise in childlessness.
Selected female cohorts
| Birth cohort | Average completed family size | Evidence status |
|---|---|---|
| 1925 | 2.12 | Observed |
| 1953 | 2.05 | Observed |
| 1979 | 1.95 | Observed |
| 2008 | 1.48 | Projected |
| 2026 | 1.43 | Projected |
Completed family size means the average number of live-born children for people assumed to have completed their families.
What is projected
Under the principal 2024-based national population projection, women born in 2008 are projected to have an average completed family size of 1.48. A girl born in 2026 is projected to average 1.43.
These figures describe what could happen under the projection’s demographic assumptions. They are not forecasts and do not predict the effects of future policy, economic conditions, or changes in behaviour.
Male cohort data
This release includes male cohort fertility for the first time. Men born in 1979 had an average of 1.82 children by age 45, compared with 1.95 completed children for women born in the same year. The male 1979 cohort is not yet a completed cohort under the ONS upper age of 65.
For the latest completed male cohort, men born in 1959 averaged 2.00 children, compared with 1.98 for women born in 1959. ONS classifies the new male cohort statistics as official statistics in development.
Plain-English interpretation
Across the selected observed generations, women had fewer children on average and reached the one-child milestone later. ONS projections suggest that the average may decline further for younger female cohorts.
This is a cohort comparison: it groups people by their own year of birth and follows cumulative fertility as they age. It is different from an annual fertility rate for births occurring in one calendar year.
Limitations
- Projected values are scenarios based on the principal national population projection, not forecasts.
- Later cohorts have not completed their reproductive years, so their final family sizes are partly or wholly projected.
- The statistics count live-born children; stillbirths, adopted or fostered children, and stepchildren are excluded.
- Birth cohort year is approximate because it is derived from calendar year and parental age at childbirth.
- Male cohort data are official statistics in development; complete digital histories are unavailable before the 1949 male cohort, and fathers’ ages are imputed for sole registrations.
- Cohort averages do not describe every person or the distribution of family sizes within a cohort.
Verification notes
- The GovDelivery newsletter was used only to discover the release and supplied no evidence for this report.
- The official ONS XLSX was downloaded and its SHA-256 hash recorded in the workbench.
- Observed values were checked in ONS workbook Tables 1a and 5; projected values were checked in Table 1b.
- Observed and projected figures are labelled separately throughout this report.
Citation and sources
Suggested citation: Office for National Statistics, “Fertility for those born in different years, England and Wales: 2024”, released 10 June 2026.
Statistical bulletin: ONS bulletin
Dataset: ONS fertility by birth cohort dataset
Quality and methods: ONS quality and methods guide