| Official Zip Code Name | Janesville |
| Zip Code State | Iowa |
| Primary County: | Bremer |
| Area Code | 319 |
| Current Population: | 37081 |
| Racial Majority: | White 62.49% |
| Median Household Income | $55618 |
| Average Adjusted Gross Income | $89060 |
| Time Zone: | 6 |
| Elevation Range | 888 ft. |
| Area | 30.397 Sqm. |
| Coordinates(Y,X) | 42.649223, -92.475572 |