| Rank | Average Family Size ▼ | School District / Population |
| 1. | 3.92 | Sugar-Salem Joint School District 322 / 4,208 |
| 2. | 3.84 | Aberdeen School District 58 / 4,107 |
| 3. | 3.84 | Snake River School District 52 / 8,116 |
| 4. | 3.79 | New Plymouth School District 372 / 4,817 |
| 5. | 3.78 | West Jefferson School District 253 / 2,470 |
| 6. | 3.77 | Jerome Joint School District 261 / 17,576 |
| 7. | 3.74 | Shelley Joint School District 60 / 8,875 |
| 8. | 3.70 | West Side Joint School District 202 / 2,535 |
| 9. | 3.69 | Murtaugh Joint School District 418 / 986 |
| 10. | 3.57 | Notus School District 135 / 1,634 |
| 11. | 3.55 | Madison School District 321 / 33,962 |
| 12. | 3.50 | Blackfoot School District 55 / 19,457 |
| 13. | 3.49 | Bonneville Joint School District 93 / 40,252 |
| 14. | 3.48 | Wendell School District 232 / 4,959 |
| 15. | 3.46 | Boundary County School District 101 / 10,748 |
| 16. | 3.46 | Jefferson County Joint School District 251 / 18,839 |
| 17. | 3.44 | Hansen School District 415 / 1,715 |
| 18. | 3.43 | Prairie Elementary School District 191 / 145 |
| 19. | 3.42 | Bruneau-Grand View Joint School District 365 / 2,901 |
| 20. | 3.40 | Marsh Valley Joint School District 21 / 6,507 |
| 21. | 3.40 | Nampa School District 131 / 79,480 |
| 22. | 3.39 | Vallivue School District 139 / 32,010 |
| 23. | 3.39 | Homedale Joint School District 370 / 5,315 |
| 24. | 3.39 | Caldwell School District 132 / 35,670 |
| 25. | 3.39 | Kuna Joint School District 3 / 20,922 |
| 26. | 3.37 | Preston Joint School District 201 / 9,466 |
| 27. | 3.37 | Middleton School District 134 / 14,292 |
| 28. | 3.36 | Cassia County Joint School District 151 / 20,487 |
| 29. | 3.35 | Horseshoe Bend School District 73 / 1,853 |
| 30. | 3.33 | Basin School District 72 / 3,638 |
| 31. | 3.33 | Wilder School District 133 / 2,578 |
| 32. | 3.33 | Fremont County Joint School District 215 / 11,387 |
| 33. | 3.32 | Rockland School District 382 / 527 |
| 34. | 3.31 | Castleford School District 417 / 1,539 |
| 35. | 3.31 | Mountain Home School District 193 / 24,083 |
| 36. | 3.30 | Minidoka County Joint School District 331 / 19,602 |
| 37. | 3.30 | North Gem School District 149 / 837 |
| 38. | 3.29 | Pocatello School District 25 / 73,921 |
| 39. | 3.28 | Firth School District 59 / 3,885 |
| 40. | 3.28 | Kimberly School District 414 / 5,563 |
| 41. | 3.26 | Post Falls School District 273 / 34,426 |
| 42. | 3.25 | Meridian Joint School District 2 / 167,895 |
| 43. | 3.25 | Glenns Ferry Joint School District 192 / 4,206 |
| 44. | 3.24 | Fruitland School District 373 / 7,802 |
| 45. | 3.24 | Lapwai School District 341 / 2,812 |
| 46. | 3.23 | Twin Falls School District 411 / 47,581 |
| 47. | 3.23 | American Falls Joint School District 381 / 7,161 |
| 48. | 3.23 | Ririe Joint School District 252 / 2,455 |
| 49. | 3.22 | Dietrich School District 314 / 697 |
| 50. | 3.21 | Idaho Falls School District 91 / 53,769 |
| 51. | 3.20 | Oneida County School District 351 / 4,024 |
| 52. | 3.20 | Plummer-Worley Joint School District 44 / 3,516 |
| 53. | 3.19 | Melba Joint School District 136 / 3,192 |
| 54. | 3.18 | Filer School District 413 / 6,551 |
| 55. | 3.18 | Blaine County School District 61 / 21,775 |
| 56. | 3.16 | Gooding Joint School District 231 / 6,079 |
| 57. | 3.16 | Parma School District 137 / 4,894 |
| 58. | 3.16 | Lake Pend Oreille School District 84 / 29,554 |
| 59. | 3.15 | Payette Joint School District 371 / 10,015 |
| 60. | 3.13 | Valley School District 262 / 2,756 |
| 61. | 3.12 | Troy School District 287 / 2,069 |
| 62. | 3.11 | Marsing Joint School District 363 / 3,432 |
| 63. | 3.08 | Kamiah Joint School District 304 / 3,839 |
| 64. | 3.06 | Lakeland Joint School District 272 / 25,538 |
| 65. | 3.03 | Emmett Independent School District 221 / 16,355 |
| 66. | 3.03 | Richfield School District 316 / 925 |
| 67. | 3.02 | Buhl Joint School District 412 / 8,637 |
| 68. | 3.01 | Coeur d'Alene School District 271 / 69,030 |
| 69. | 3.01 | Shoshone Joint School District 312 / 2,810 |
| 70. | 3.01 | West Bonner County School District 83 / 11,224 |
| 71. | 3.01 | Nezperce Joint School District 302 / 833 |
| 72. | 3.01 | Bliss Joint School District 234 / 642 |
| 73. | 3.00 | Soda Springs Joint School District 150 / 4,462 |
| 74. | 3.00 | Potlatch School District 285 / 3,145 |
| 75. | 2.99 | Culdesac Joint School District 342 / 734 |
| 76. | 2.97 | Kendrick Joint School District 283 / 2,041 |
| 77. | 2.96 | Moscow School District 281 / 27,674 |
| 78. | 2.96 | Boise City Independent School District 1 / 182,560 |
| 79. | 2.96 | Hagerman Joint School District 233 / 2,412 |
| 80. | 2.95 | Teton County School District 401 / 8,422 |
| 81. | 2.94 | Lewiston Independent School District 340 / 33,761 |
| 82. | 2.94 | Salmon School District 291 / 7,040 |
| 83. | 2.94 | Cottonwood Joint School District 242 / 2,933 |
| 84. | 2.90 | Weiser School District 431 / 8,353 |
| 85. | 2.89 | Camas County School District 121 / 1,040 |
| 86. | 2.89 | St. Maries Joint School District 41 / 6,960 |
| 87. | 2.87 | Highland Joint School District 305 / 1,666 |
| 88. | 2.86 | Kellogg Joint School District 391 / 8,688 |
| 89. | 2.86 | Three Creek Joint Elementary School District 416 / 31 |
| 90. | 2.86 | Mountain View School District 244 / 9,115 |
| 91. | 2.84 | Pleasant Valley Elementary School District 364 / 181 |
| 92. | 2.82 | Genesee Joint School District 282 / 1,543 |
| 93. | 2.81 | Avery School District 394 / 369 |
| 94. | 2.79 | Bear Lake County School District 33 / 5,771 |
| 95. | 2.78 | Butte County Joint School District 111 / 2,668 |
| 96. | 2.78 | Grace Joint School District 148 / 1,982 |
| 97. | 2.76 | Mullan School District 392 / 936 |
| 98. | 2.73 | Challis Joint School District 181 / 3,197 |
| 99. | 2.73 | Meadows Valley School District 11 / 1,152 |
| 100. | 2.72 | Clark County School District 161 / 984 |
| 101. | 2.68 | South Lemhi School District 292 / 531 |
| 102. | 2.67 | Whitepine Joint School District 288 / 1,733 |
| 103. | 2.67 | Kootenai Joint School District 274 / 2,105 |
| 104. | 2.66 | Council School District 13 / 2,007 |
| 105. | 2.64 | Swan Valley Elementary School District 92 / 606 |
| 106. | 2.64 | Wallace School District 393 / 4,033 |
| 107. | 2.63 | McCall-Donnelly Joint School District 421 / 6,187 |
| 108. | 2.61 | Cambridge Joint School District 432 / 1,156 |
| 109. | 2.60 | Cascade School District 422 / 2,528 |
| 110. | 2.60 | Mackay Joint School District 182 / 1,280 |
| 111. | 2.56 | Garden Valley School District 71 / 1,976 |
| 112. | 2.54 | Arbon Elementary School District 383 / 111 |
| 113. | 2.52 | Orofino Joint School District 171 / 8,550 |
| 114. | 2.49 | Midvale School District 433 / 648 |
| 115. | 2.24 | Salmon River School District 243 / 944 |
Please note that we only rank locations with 'Average Family Size' data. The rank above might not be a complete list. Locations without 'Average Family Size' data are not listed.
*ACS stands for U.S. Census American Community Survey. According to the U.S. Census, if the date is a range, you can interpret the data as an average of the period of time.
