Last official estimated population of New Castle County was 538,873 (year 2014)[1]. This was 0.169% of total US population and 57% of total Delaware state population. Area of New Castle County is 494.0 mi² (=1279.5 km²), in this year population density was 1,090.83 p/mi². If population growth rate would be same as in period 2010-2014 (+0.02%/yr), New Castle County population in 2025 would be 539,958 [0].
Historical population of New Castle County for period 1790-2014 [1] , [2] , [3]:
Estimated population for 2014[1]. Population density is in p./sq.mi [4]. Changes are for period 2010-2015. Value is %/year. Boundary lines are approx. 2012 [5]. Click on flag to hide it.
Population • Density • Changes • Legends • Position

[1790-1800] +2.56 %/yr
[1800-1810] -0.37 %/yr
[1810-1820] +1.34 %/yr
[1820-1830] +0.63 %/yr
[1830-1840] +1.09 %/yr
[1840-1850] +2.59 %/yr
[1850-1860] +2.51 %/yr
[1860-1870] +1.49 %/yr
[1870-1880] +2.04 %/yr
[1880-1890] +2.26 %/yr
[1890-1900] +1.22 %/yr
[1900-1910] +1.17 %/yr
[1910-1920] +1.87 %/yr
[1920-1930] +0.83 %/yr
[1930-1940] +1.1 %/yr
[1940-1950] +2 %/yr
[1950-1960] +3.46 %/yr
[1960-1970] +2.3 %/yr
[1970-1980] +0.31 %/yr
[1980-1990] +1.05 %/yr
[1990-2000] +1.25 %/yr
[2000-2005] +0.9 %/yr
[2005-2010] +0.57 %/yr
[2010-2014] +0.02 %/yr
Looking for settlements in New Castle County? Visit this page: Settlements in New Castle County, DE
Population of New Castle County by age groups male (M) and female (F)[1b]
| Age Gr. | (M) | (F) | Total |
| 0 to 4 | 16883 | 16597 | 33,480 |
| 5 to 9 | 16820 | 16625 | 33,445 |
| 10 to 14 | 17643 | 16936 | 34,579 |
| 15 to 19 | 19063 | 18863 | 37,926 |
| 20 to 24 | 20023 | 19600 | 39,623 |
| 25 to 29 | 20379 | 20888 | 41,267 |
| 30 to 34 | 18505 | 18866 | 37,371 |
| 35 to 39 | 16545 | 17146 | 33,691 |
| 40 to 44 | 17475 | 18123 | 35,598 |
| 45 to 49 | 18223 | 19928 | 38,151 |
| 50 to 54 | 19702 | 21377 | 41,079 |
| 55 to 59 | 18648 | 20179 | 38,827 |
| 60 to 64 | 14794 | 16904 | 31,698 |
| 65 to 69 | 11771 | 13579 | 25,350 |
| 70 to 74 | 8020 | 9995 | 18,015 |
| 75 to 79 | 5539 | 7185 | 12,724 |
| 80 to 84 | 3942 | 5701 | 9,643 |
| 85+ | 3567 | 6744 | 10,311 |
New Castle County resident population estimates by Sex, Race, and Hispanic Origin[1b]. For full list of abbrevations see: population.us/about page.
| Race | Male | Female | Total |
| NH | 241072 | 259859 | 500,931 |
| WAC | 186618 | 195089 | 381,707 |
| WA | 181385 | 189406 | 370,791 |
| NHWAC | 164125 | 174170 | 338,295 |
| NHWA | 159578 | 169304 | 328,882 |
| BAC | 68824 | 77664 | 146,488 |
| NHBAC | 65310 | 73570 | 138,880 |
| BA | 64748 | 73068 | 137,816 |
| NHBA | 61806 | 69706 | 131,512 |
| H | 26470 | 25377 | 51,847 |
| HWAC | 22493 | 20919 | 43,412 |
| HWA | 21807 | 20102 | 41,909 |
| AAC | 15630 | 16458 | 32,088 |
| NHAAC | 15356 | 16119 | 31,475 |
| AA | 13958 | 14660 | 28,618 |
| NHAA | 13820 | 14476 | 28,296 |
| TOM | 6100 | 6781 | 12,881 |
| NHTOM | 5294 | 5797 | 11,091 |
| HBAC | 3514 | 4094 | 7,608 |
| HBA | 2942 | 3362 | 6,304 |
| IAC | 2674 | 2961 | 5,635 |
| NHIAC | 1721 | 1987 | 3,708 |
| IA | 1164 | 1130 | 2,294 |
| HIAC | 953 | 974 | 1,927 |
| HTOM | 806 | 984 | 1,790 |
| HIA | 661 | 627 | 1,288 |
| NHIA | 503 | 503 | 1,006 |
| NAC | 338 | 402 | 740 |
| HAAC | 274 | 339 | 613 |
| NHNAC | 188 | 231 | 419 |
| NA | 187 | 191 | 378 |
| HAA | 138 | 184 | 322 |
| HNAC | 150 | 171 | 321 |
| HNA | 116 | 118 | 234 |
| NHNA | 71 | 73 | 144 |
• Delaware County population
26.9 mi,
28°
• Camden County
39.5 mi,
66°
• Chester County
28.1 mi,
348°
• Gloucester County
28.4 mi,
69°
• Harford County
35 mi,
265°
• Kent County
33.9 mi,
167°
• Cumberland County
32.7 mi,
121°
• Cecil County
15.9 mi,
266°
• Salem County
15.3 mi,
90°
• Kent County
34.6 mi,
228°
[0] Calculated by population.us from last known population growth rate, not official data.
[1] County population - 2014, archived from the original, retrieved 02/23/2016
[1b] Annual County Resident Population Estimates by Age, Sex, Race, and Hispanic Origin, (used only data for 2014) archived from the original, retrieved 02/23/2016
[2] County population - 2000-2010, archived from the original, retrieved 02/23/2016
[3] Population of States and Counties of the United States: 1790 to 1992, PDF, 15 Mb, census.gov, retrieved 02/23/2016
[4] County area, latitude longitude data, retrieved 02/23/2016
[5] County boundaries, CSV files on boundaries.us, retrived 03/18/2016
Page generated in 0.002 seconds© 2016 population.us | Terms of use | Contact