Ranking of US Counties By Number of Adults (18-64yrs) in 2021 (ACS-5Yrs)

Updated on July 9, 2024.

Based on the US Census ACS-5Yrs estimates, in 2021, among all US counties, Los Angeles County, CA had the highest number of adults (18-64yrs) (6.48M), followed by Cook County, IL (3.34M), and Harris County, TX (2.94M).

The chart below shows the top 10 counties, and the table below shows the top 200 counties.

You can see similar info for other age cohorts.

Related Topics: US Census 2021 Topic List.
Ranking of US Counties By Number of Adults (18-64yrs) in 2021
Los Angeles County, CA
Cook County, IL
Harris County, TX
Maricopa County, AZ
San Diego County, CA
Orange County, CA
Kings County, NY
Miami-Dade County, FL
Dallas County, TX
Queens County, NY
Ranking of US Counties By Number of Adults (18-64yrs) in 2021
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Rank County Adults (18-64yrs) Pop.
1 Los Angeles County, CA 6478335
2 Cook County, IL 3339472
3 Harris County, TX 2943798
4 Maricopa County, AZ 2667950
5 San Diego County, CA 2117615
6 Orange County, CA 2010817
7 Kings County, NY 1707584
8 Miami-Dade County, FL 1704001
9 Dallas County, TX 1643121
10 Queens County, NY 1525184
11 King County, WA 1493834
12 Riverside County, CA 1457318
13 Clark County, NV 1384135
14 San Bernardino County, CA 1346180
15 Tarrant County, TX 1304486
16 Santa Clara County, CA 1248070
17 Bexar County, TX 1241988
18 Broward County, FL 1201029
19 New York County, NY 1146850
20 Alameda County, CA 1095049
21 Wayne County, MI 1086997
22 Middlesex County, MA 1054043
23 Philadelphia County, PA 1029132
24 Sacramento County, CA 978120
25 Suffolk County, NY 943079
26 Orange County, FL 928758
27 Hillsborough County, FL 915997
28 Bronx County, NY 911303
29 Travis County, TX 869416
30 Franklin County, OH 847706
31 Palm Beach County, FL 844627
32 Nassau County, NY 842848
33 Hennepin County, MN 810239
34 Oakland County, MI 790687
35 Allegheny County, PA 775224
36 Cuyahoga County, OH 771066
37 Salt Lake County, UT 729411
38 Fairfax County, VA 720678
39 Mecklenburg County, NC 718646
40 Wake County, NC 716650
41 Contra Costa County, CA 714104
42 Fulton County, GA 702232
43 Collin County, TX 657090
44 Montgomery County, MD 645747
45 Duval County, FL 620493
46 Honolulu County, HI 618464
47 Pima County, AZ 614467
48 Prince George's County, MD 614405
49 San Francisco County, CA 609786
50 Westchester County, NY 609588
51 Marion County, IN 607196
52 St. Louis County, MO 598459
53 Gwinnett County, GA 596662
54 Fresno County, CA 594999
55 Fairfield County, CT 590133
56 Bergen County, NJ 586151
57 Erie County, NY 585468
58 Milwaukee County, WI 584724
59 Denton County, TX 576027
60 DuPage County, IL 574507
61 Pierce County, WA 571324
62 Shelby County, TN 568333
63 Suffolk County, MA 565850
64 Pinellas County, FL 565570
65 Hartford County, CT 556123
66 Multnomah County, OR 549833
67 Macomb County, MI 543953
68 Kern County, CA 543636
69 Worcester County, MA 541580
70 Middlesex County, NJ 541267
71 New Haven County, CT 539357
72 Essex County, NJ 532755
73 Snohomish County, WA 523102
74 El Paso County, TX 522516
75 Ventura County, CA 519518
76 Baltimore County, MD 518879
77 Montgomery County, PA 515914
78 Hamilton County, OH 508570
79 Essex County, MA 495751
80 Fort Bend County, TX 493622
81 Hidalgo County, TX 489212
82 Cobb County, GA 488795
83 Denver County, CO 488117
84 DeKalb County, GA 487726
85 San Mateo County, CA 482834
86 Hudson County, NJ 481699
87 Jefferson County, KY 480784
88 Oklahoma County, OK 479688
89 Davidson County, TN 473829
90 Monroe County, NY 467549
91 San Joaquin County, CA 464368
92 El Paso County, CO 456329
93 Norfolk County, MA 449097
94 Lake County, IL 439167
95 Jackson County, MO 437517
96 Will County, IL 432167
97 Providence County, RI 420738
98 Bernalillo County, NM 417797
99 Arapahoe County, CO 412713
100 Polk County, FL 412539
101 Jefferson County, AL 411016
102 Kent County, MI 406883
103 Lee County, FL 405768
104 Tulsa County, OK 399940
105 Monmouth County, NJ 391950
106 Bucks County, PA 391540
107 Baltimore city, MD 387024
108 Utah County, UT 383865
109 Washington County, OR 381230
110 Jefferson County, CO 370560
111 Johnson County, KS 369761
112 Williamson County, TX 369330
113 Montgomery County, TX 367921
114 Anne Arundel County, MD 366579
115 Dane County, WI 365229
116 Bristol County, MA 359258
117 New Castle County, DE 355906
118 Union County, NJ 354801
119 Douglas County, NE 354414
120 Delaware County, PA 352565
121 Brevard County, FL 349218
122 Ramsey County, MN 341016
123 Ocean County, NJ 335790
124 Guilford County, NC 335237
125 Summit County, OH 329516
126 Stanislaus County, CA 329206
127 Spokane County, WA 327777
128 Adams County, CO 325510
129 Chester County, PA 323601
130 Montgomery County, OH 321373
131 Lancaster County, PA 321320
132 Camden County, NJ 320400
133 Passaic County, NJ 320141
134 Plymouth County, MA 318794
135 Volusia County, FL 317584
136 Greenville County, SC 316972
137 Pasco County, FL 316567
138 Kane County, IL 315397
139 Morris County, NJ 314356
140 Sedgwick County, KS 310841
141 Richmond County, NY 304541
142 Polk County, IA 303308
143 Clark County, WA 301363
144 Ada County, ID 300600
145 Prince William County, VA 300314
146 Knox County, TN 299886
147 Sonoma County, CA 297887
148 Washoe County, NV 297296
149 Lake County, IN 297225
150 Seminole County, FL 295887
151 Onondaga County, NY 291747
152 Virginia Beach city, VA 290335
153 Hampden County, MA 287090
154 Burlington County, NJ 285739
155 East Baton Rouge Parish, LA 285675
156 Solano County, CA 279243
157 Santa Barbara County, CA 278922
158 York County, PA 274338
159 Tulare County, CA 272762
160 Richland County, SC 271525
161 Hillsborough County, NH 268316
162 Dakota County, MN 266809
163 Jefferson Parish, LA 265574
164 Monterey County, CA 263580
165 Lucas County, OH 260864
166 Loudoun County, VA 258736
167 Charleston County, SC 258343
168 Berks County, PA 257854
169 Clackamas County, OR 252446
170 Washtenaw County, MI 250186
171 Mobile County, AL 249335
172 Orleans Parish, LA 248886
173 St. Charles County, MO 246909
174 Genesee County, MI 243474
175 Mercer County, NJ 243368
176 Pulaski County, AR 242754
177 Waukesha County, WI 242376
178 Madison County, AL 241198
179 Orange County, NY 240251
180 Pinal County, AZ 239821
181 Butler County, OH 238950
182 Osceola County, FL 237744
183 Lane County, OR 236777
184 Cameron County, TX 236680
185 Placer County, CA 233114
186 Forsyth County, NC 231976
187 Larimer County, CO 229549
188 Allen County, IN 227741
189 Brazoria County, TX 227732
190 Lehigh County, PA 225510
191 Hamilton County, TN 223832
192 Bell County, TX 223509
193 Anoka County, MN 223254
194 Stark County, OH 221015
195 Chesterfield County, VA 219717
196 Douglas County, CO 219552
197 Boulder County, CO 218304
198 Rutherford County, TN 217128
199 Nueces County, TX 215149
200 Somerset County, NJ 214377