Home / Places / East of England / Hertfordshire ONS estimates show that the county council area's population rose by 119,574 residents (10.7%) between mid-2011 and mid-2025, from 1,119,824 to 1,239,398. Source: ONS MYE4 .
1,239,398 Residents, mid-2025 ONS MYE4 estimate 1,198,798 Residents, Census 2021 ethnicity table ONS TS021 county row 1,116,062 Residents, Census 2011 ONS KS201EW county row Ethnic groups in the county council area Census 2011
White British 80.8% White Other 6.8% Asian 6.5% Black 2.8% Mixed 2.5% Other 0.6% Census 2021
White British 71.8% White Other 9.9% Asian 8.6% Black 3.7% Mixed 3.8% Other 2.1% Published county counts. Changes are percentage points calculated from unrounded shares. Group 2011 2021 Change White British 902,006 861,006 -9.0pp White Other 75,489 119,055 +3.2pp Asian 72,581 103,668 +2.1pp Black 31,401 44,894 +0.9pp Mixed 27,497 45,126 +1.3pp Other 7,088 25,049 +1.5pp
How county and district counts relate County figures use the ONS county council row. Districts use their own published rows. Census 2021 counts include disclosure-control changes, so district figures may not add exactly to the county figure. The reconciliation table shows each difference. Census 2011 counts and annual population estimates agree exactly with the district sums.
The 2021 district total is 5 residents higher than the published county total. Both figures are retained as published. The ethnicity table's all-residents count is the denominator for every county ethnic group share.
ONS explains Census 2021 disclosure controls . The audit does not establish the precise cause of each individual difference.
Reconciliation: every county and district-sum comparison Difference means district sum minus published county count. Year and measure County District sum Difference 2011: All residents 1,116,062 1,116,062 0 2011: White British 902,006 902,006 0 2011: White Other 75,489 75,489 0 2011: Asian 72,581 72,581 0 2011: Black 31,401 31,401 0 2011: Mixed 27,497 27,497 0 2011: Other 7,088 7,088 0 2021: All residents 1,198,798 1,198,803 +5 2021: White British 861,006 861,006 0 2021: White Other 119,055 119,055 0 2021: Asian 103,668 103,673 +5 2021: Black 44,894 44,893 -1 2021: Mixed 45,126 45,127 +1 2021: Other 25,049 25,049 0
Raw source rows: KS201EW, 2011 , row 80. TS021, 2021 , row 138.
Download all county reconciliation records (CSV)
Annual county population estimates, 2011 to 2025 ONS MYE4. Every value agrees exactly with the sum of constituent districts. Year Residents 2011 1,119,824 2012 1,131,536 2013 1,143,681 2014 1,156,321 2015 1,167,308 2016 1,180,234 2017 1,185,014 2018 1,188,182 2019 1,193,394 2020 1,198,052 2021 1,200,899 2022 1,206,101 2023 1,220,700 2024 1,233,983 2025 1,239,398
Population change since 2011 Map: Population change since 2011, mid-2025 estimate. Hertfordshire: 10 district councils. Broxbourne +10.1%; Dacorum +11.7%; East Hertfordshire +14.4%; Hertsmere +9.8%; North Hertfordshire +7.7%; St Albans +6.7%; Stevenage +9.3%; Three Rivers +9.3%; Watford +18.8%; Welwyn Hatfield +10.0%. Broxbourne: +10.1% Dacorum: +11.7% East Hertfordshire: +14.4% Hertsmere: +9.8% North Hertfordshire: +7.7% St Albans: +6.7% Stevenage: +9.3% Three Rivers: +9.3% Watford: +18.8% Welwyn Hatfield: +10.0% East Hertfordshire +14.4% 158,033 people St Albans +6.7% 150,757 people North Hertfordshire +7.7% 137,365 people Three Rivers +9.3% 96,068 people Broxbourne +10.1% 103,130 people ukdemographics.co.uk ukdemographics.co.uk UK Demographics Population data for every community 2025 Population change since 2011 Hertfordshire: 10 district councils ONS ESTIMATE −4 −1 +1 +4 +8 +12% Change in the estimated resident population at 30 June, compared with mid-2011. Source: ONS, Mid-Year Population Estimates, England and Wales, June 2025, table MYE4 (published 29 July 2026). Boundaries: ONS LAD (May 2026) BSC. Contains OS data © Crown copyright and database right 2026. ukdemographics.co.uk Every figure sourced. Map: Population change since 2011, mid-2025 estimate. Hertfordshire: 10 district councils. Broxbourne +10.1%; Dacorum +11.7%; East Hertfordshire +14.4%; Hertsmere +9.8%; North Hertfordshire +7.7%; St Albans +6.7%; Stevenage +9.3%; Three Rivers +9.3%; Watford +18.8%; Welwyn Hatfield +10.0%. Broxbourne: +10.1% Dacorum: +11.7% East Hertfordshire: +14.4% Hertsmere: +9.8% North Hertfordshire: +7.7% St Albans: +6.7% Stevenage: +9.3% Three Rivers: +9.3% Watford: +18.8% Welwyn Hatfield: +10.0% East Hertfordshire +14.4% 158,033 people St Albans +6.7% 150,757 people North Hertfordshire +7.7% 137,365 people Dacorum +11.7% 162,316 people Welwyn Hatfield +10.0% 121,748 people Hertsmere +9.8% 110,242 people Three Rivers +9.3% 96,068 people Broxbourne +10.1% 103,130 people Watford +18.8% 107,658 people Stevenage +9.3% 92,081 people ukdemographics.co.uk ukdemographics.co.uk UK Demographics Population data for every community 2025 Population change since 2011 Hertfordshire: 10 district councils ONS ESTIMATE −4 −1 +1 +4 +8 +12% Change in the estimated resident population at 30 June, compared with mid-2011. Source: ONS, Mid-Year Population Estimates, England and Wales, June 2025, table MYE4 (published 29 July 2026). Boundaries: ONS LAD (May 2026) BSC. Contains OS data © Crown copyright and database right 2026. ukdemographics.co.uk Every figure sourced. ONS mid-year estimates. Councils A to Z. Council 2011 2025 Change Broxbourne 93,702 103,130 +10.1% Dacorum 145,298 162,316 +11.7% East Hertfordshire 138,155 158,033 +14.4% Hertsmere 100,379 110,242 +9.8% North Hertfordshire 127,494 137,365 +7.7% St Albans 141,248 150,757 +6.7% Stevenage 84,247 92,081 +9.3% Three Rivers 87,921 96,068 +9.3% Watford 90,653 107,658 +18.8% Welwyn Hatfield 110,727 121,748 +10.0%
Census 2021 ethnic groups Map: White British share of residents, Census 2021. Hertfordshire: 10 district councils. Broxbourne 68.6%; Dacorum 78.7%; East Hertfordshire 84.7%; Hertsmere 63.1%; North Hertfordshire 81.3%; St Albans 73.5%; Stevenage 75.3%; Three Rivers 67.9%; Watford 45.8%; Welwyn Hatfield 67.2%. England and Wales 2021: 74.4%. Broxbourne: 68.6% Dacorum: 78.7% East Hertfordshire: 84.7% Hertsmere: 63.1% North Hertfordshire: 81.3% St Albans: 73.5% Stevenage: 75.3% Three Rivers: 67.9% Watford: 45.8% Welwyn Hatfield: 67.2% East Hertfordshire 84.7% fell 5.5 points from 2011 St Albans 73.5% fell 7.6 points from 2011 Three Rivers 67.9% fell 11.7 points from 2011 ukdemographics.co.uk ukdemographics.co.uk UK Demographics Population data for every community 2021 White British share of residents Hertfordshire: 10 district councils CENSUS · OBSERVED 40 50 60 70 80 90% England and Wales 2011: 80.5% England and Wales 2021: 74.4% Share of usual residents in the White: English, Welsh, Scottish, Northern Irish or British group. Source: ONS Census 2011, table KS201EW. Boundaries: ONS LAD (May 2026) BSC. Contains OS data © Crown copyright and database right 2026. Share of usual residents in the White: English, Welsh, Scottish, Northern Irish or British group. Source: ONS Census 2021, table TS021; change from Census 2011, table KS201EW. Boundaries: ONS LAD (May 2026) BSC. Contains OS data © Crown copyright and database right 2026. ukdemographics.co.uk Every figure sourced. Map: White British share of residents, Census 2021. Hertfordshire: 10 district councils. Broxbourne 68.6%; Dacorum 78.7%; East Hertfordshire 84.7%; Hertsmere 63.1%; North Hertfordshire 81.3%; St Albans 73.5%; Stevenage 75.3%; Three Rivers 67.9%; Watford 45.8%; Welwyn Hatfield 67.2%. England and Wales 2021: 74.4%. Broxbourne: 68.6% Dacorum: 78.7% East Hertfordshire: 84.7% Hertsmere: 63.1% North Hertfordshire: 81.3% St Albans: 73.5% Stevenage: 75.3% Three Rivers: 67.9% Watford: 45.8% Welwyn Hatfield: 67.2% East Hertfordshire 84.7% fell 5.5 points from 2011 St Albans 73.5% fell 7.6 points from 2011 North Hertfordshire 81.3% fell 3.6 points from 2011 Dacorum 78.7% fell 7.2 points from 2011 Hertsmere 63.1% fell 12.6 points from 2011 Three Rivers 67.9% fell 11.7 points from 2011 Broxbourne 68.6% fell 12.3 points from 2011 Watford 45.8% fell 16.1 points from 2011 Stevenage 75.3% fell 7.8 points from 2011 Welwyn Hatfield 67.2% fell 9.3 points from 2011 ukdemographics.co.uk ukdemographics.co.uk UK Demographics Population data for every community 2021 White British share of residents Hertfordshire: 10 district councils CENSUS · OBSERVED 40 50 60 70 80 90% England and Wales 2021: 74.4% Share of usual residents in the White: English, Welsh, Scottish, Northern Irish or British group. Source: ONS Census 2011, table KS201EW. Boundaries: ONS LAD (May 2026) BSC. Contains OS data © Crown copyright and database right 2026. Share of usual residents in the White: English, Welsh, Scottish, Northern Irish or British group. Source: ONS Census 2021, table TS021; change from Census 2011, table KS201EW. Boundaries: ONS LAD (May 2026) BSC. Contains OS data © Crown copyright and database right 2026. ukdemographics.co.uk Every figure sourced. Each bar shows all six groups. Figures are observed Census 2021 shares; they are not projections.
White British 68.6% White Other 12.5% Asian 3.7% Black 6.7% Mixed 4.0% Other 4.6% White British 78.7% White Other 8.1% Asian 5.8% Black 2.8% Mixed 3.4% Other 1.2% White British 84.7% White Other 7.5% Asian 2.7% Black 1.3% Mixed 2.8% Other 0.9% White British 63.1% White Other 14.0% Asian 10.5% Black 4.8% Mixed 3.7% Other 3.8% White British 81.3% White Other 6.3% Asian 5.2% Black 2.4% Mixed 3.7% Other 1.1% White British 73.5% White Other 10.1% Asian 8.2% Black 2.1% Mixed 4.3% Other 1.8% White British 75.3% White Other 7.5% Asian 7.5% Black 4.8% Mixed 3.6% Other 1.3% White British 67.9% White Other 9.2% Asian 15.2% Black 2.4% Mixed 3.6% Other 1.7% White British 45.8% White Other 15.1% Asian 24.5% Black 6.3% Mixed 4.7% Other 3.6% White British 67.2% White Other 11.5% Asian 8.8% Black 6.1% Mixed 4.1% Other 2.3% Sources: ONS MYE4 population estimates, Census 2011 KS201EW and Census 2021 TS021. Boundaries: ONS Open Geography. Contains public sector information licensed under the Open Government Licence v3.0.
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