ZIP Code 37321 — Dayton, TN
37321 is a standard (street delivery) ZIP code serving Dayton, Tennessee, in Rhea County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 37321 at a glance
| ZIP code | 37321 |
|---|---|
| Primary city | Dayton |
| State | Tennessee (TN) |
| County | Rhea FIPS 47143 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 21,084 |
| Coordinates | 35.502390, -85.008010 |
How ZIP+4 works in 37321
The four digits after the hyphen encode a delivery segment inside 37321. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 37321 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 37321.
| ZIP | City | Distance |
|---|---|---|
| 37332 | Evensville, TN | 6.8 mi |
| 37373 | Sale Creek, TN | 9.2 mi |
| 37308 | Birchwood, TN | 10.7 mi |
| 37322 | Decatur, TN | 10.8 mi |
| 37338 | Graysville, TN | 12.6 mi |
| 37336 | Georgetown, TN | 14.5 mi |
| 37381 | Spring City, TN | 14.6 mi |
| 37367 | Pikeville, TN | 14.7 mi |
| 37379 | Soddy Daisy, TN | 17.1 mi |
| 37370 | Riceville, TN | 19.9 mi |
| 37309 | Calhoun, TN | 20.1 mi |
| 37312 | Cleveland, TN | 20.3 mi |
Questions about 37321
What is the ZIP+4 code for 37321?
37321 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 37321, you need to look up a specific street address to get them.
What city is 37321?
37321 is assigned to Dayton, Tennessee, in Rhea County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.