ZIP Code 16057 — Slippery Rock, PA
16057 is a standard (street delivery) ZIP code serving Slippery Rock, Pennsylvania, in Butler 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 16057 at a glance
| ZIP code | 16057 |
|---|---|
| Primary city | Slippery Rock |
| State | Pennsylvania (PA) |
| County | Butler FIPS 42019 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 15,718 |
| Coordinates | 41.034270, -80.057900 |
How ZIP+4 works in 16057
The four digits after the hyphen encode a delivery segment inside 16057. 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 16057 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 16057.
| ZIP | City | Distance |
|---|---|---|
| 16035 | Forestville, PA | 5.5 mi |
| 16051 | Portersville, PA | 7.6 mi |
| 16052 | Prospect, PA | 8.9 mi |
| 16061 | West Sunbury, PA | 9.1 mi |
| 16156 | Volant, PA | 9.5 mi |
| 16127 | Grove City, PA | 9.7 mi |
| 16020 | Boyers, PA | 10.1 mi |
| 16038 | Harrisville, PA | 10.3 mi |
| 16001 | Butler, PA | 10.4 mi |
| 16040 | Hilliards, PA | 11.8 mi |
| 16101 | New Castle, PA | 12.4 mi |
| 16037 | Harmony, PA | 13.1 mi |
Questions about 16057
What is the ZIP+4 code for 16057?
16057 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 16057, you need to look up a specific street address to get them.
What city is 16057?
16057 is assigned to Slippery Rock, Pennsylvania, in Butler 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.