What the ZIP Code Radius Finder does
This finder lists every US ZIP code within a radius of a ZIP code or a latitude and longitude - each with its place name, state, county and straight-line distance, sorted nearest first - and counts how many fall in each state. Copy the ZIP codes as a comma-separated list or download the whole table as CSV for a delivery area, a sales territory or an ad-targeting list.
The search runs in your browser against the GeoNames postal export, vendored on a2z.tools and loaded once (about 600 KB). No geocoder, map tile or address service is called, so nothing you type is sent anywhere. Each ZIP code is represented by one approximate centre point, which is the main thing to keep in mind when reading the result.
How to use it
- Type a five-digit ZIP code such as 10001, or coordinates such as 40.7484, -73.9967. ZIP+4 codes and degrees-minutes-seconds are accepted.
- Enter the radius and choose miles or kilometres. The maximum is 500 miles (805 km).
- Press Find ZIP codes. The first search loads the US postal file; later searches are instant.
- Read the count at the top and the state breakdown, then the table, which is sorted nearest first and can be re-sorted or filtered by any column.
- Copy the ZIP list for pasting into a form, or download the CSV with place, state, county, coordinates and distance.
Reading the results
The distance is the great-circle (straight-line) distance between ZIP centre points. Driving distance is typically longer - often by a fifth to a half, more around water, mountains or sparse road networks.
A ZIP code is listed when its centre point is inside the circle. Large rural ZIP codes can cover ground well inside your radius while their centre point sits just outside, so treat ZIP codes near the edge as borderline either way.
The centre ZIP itself is listed first at distance 0. Codes that share one centre point in the data - common for PO box codes in the same post office - appear at the same distance.
The state count shows how a radius spills across state lines, which matters for licensing, sales tax and service-area rules.
Worked example: 25 miles round ZIP 10001 in Midtown Manhattan
ZIP 10001's centre point in the GeoNames file is 40.7484, -73.9967. A 25-mile radius is 25 x 1,609.344 = 40,233.6 metres.
The search finds 671 ZIP code centre points inside that circle: 433 in New York and 238 in New Jersey. The nearest other New Jersey code is under 2 miles away across the Hudson, which is why a radius round Manhattan always reaches into New Jersey.
The CSV has one line per ZIP code with its distance, so you can sort by county or cut the list at 10 miles without searching again.
Counts depend on the data release; a newer GeoNames file may add or retire a few codes.
Formulas and scoring rules
- Great-circle distance (haversine)
a = sin^2(dLat/2) + cos(lat1) cos(lat2) sin^2(dLon/2); d = 2 R asin(sqrt(a))R = 6,371,008.8 m, the IUGG mean Earth radius. Over a few hundred miles the spherical model differs from the ellipsoid by well under 0.5%.- Units
1 mile = 1,609.344 m exactly; 1 km = 1,000 m- Inclusion rule
listed when d(centre, ZIP centroid) <= radiusA latitude-longitude box is used to skip far-away rows first; a test checks the result against a scan of every row.
How this differs from the postal code distance and finder tools
The Postal Code Distance Calculator measures between codes you already have, and the Worldwide Postal Code Finder looks up a single code. This tool searches outward from one point: every US ZIP code inside a radius, sorted nearest first, counted by state and exported as CSV. It covers the United States only.
What the GeoNames data does and does not include
GeoNames publishes one row per ZIP code with a place name, state, county and a representative coordinate, under the Creative Commons Attribution 4.0 licence. It is not the US Postal Service's own database, which is licensed. Puerto Rico, Guam and the US Virgin Islands are separate country files in GeoNames and are not searched here. Unique ZIP codes assigned to one large organisation, PO-box-only codes and very new codes may be missing or may share a coordinate with a nearby post office.
Limitations: what the result does not prove
- ZIP centroids are approximate points. A ZIP code is a set of delivery routes, not a polygon, so this cannot tell you whether a particular address is inside your radius.
- Distances are straight-line, not driving or travel time.
- The data is a dated GeoNames export, not the live USPS ZIP list. Codes are added, retired and re-drawn over time.
- The list is capped at 5,000 ZIP codes and the radius at 500 miles, so the page stays usable.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- GeoNames postal code export (CC BY 4.0) - checked 19 Sep 2026
- GeoNames postal code export (CC BY 4.0)
- Creative Commons Attribution 4.0 International licence
- US Census Bureau - ZIP Code Tabulation Areas (why ZIP codes are not areas)
- NIST - definition of the international mile (1 mile = 1,609.344 m)
Frequently asked questions
How do I find all ZIP codes within a radius?
Enter the centre ZIP code or its coordinates, set the radius in miles or kilometres and press Find ZIP codes. Every ZIP whose centre point lies inside the circle is listed nearest first, with a CSV download and a copyable list.
How many ZIP codes are within 10 miles of me?
It varies enormously with density - about 300 round Midtown Manhattan (10001), but just one round Miles City in eastern Montana (59301). Enter your ZIP code with a 10-mile radius to get the count, broken down by state.
Is the ZIP code radius distance driving distance?
No. It is the straight-line distance between ZIP centre points. Road distance is longer, often noticeably so near rivers, coasts and mountains. Use a route planner for travel distance.
Can I search a radius from an address or a city name?
Not directly, because this page does not send what you type to a geocoding service. Enter the address's ZIP code, or copy its latitude and longitude from a map app and paste them here.
Why is a ZIP code next to mine missing from the radius?
Either its centre point is just outside the circle - large rural ZIP codes have centres far from their edges - or it is a PO-box or single-organisation code not in the GeoNames file. Try a slightly larger radius to check.
Does the ZIP radius search include Puerto Rico?
No. GeoNames publishes Puerto Rico and the other US territories as separate country files, and this tool searches the United States file only. The postal code finder pages cover those territories individually.
Last reviewed by the A2Z.Tools team against the sources listed above.
